Use feature flags to configure the gas estimation buffers, including
support for specific chain and type-4 buffers.

```js
[FeatureFlag.GasBuffer]?: {
    /** Fallback buffer for all chains and transactions. */
    default?: number;

    /**
     * Buffer for included network RPCs only and not those added by user.
     * Takes priority over `default`.
     */
    included?: number;

    /** Buffers for specific chains. */
    perChainConfig?: {
      [chainId: Hex]: {
        /**
         * Buffer for the chain for all transactions.
         * Takes priority over non-chain `included`.
         */
        base?: number;

        /**
         * Buffer if network RPC is included and not added by user.
         * Takes priority over `base`.
         */
        included?: number;

        /**
         * Buffer for the chain for EIP-7702 / type 4 transactions only.
         * Only if `data` included and `to` matches `from`.
         * Takes priority over `included` and `base`.
         */
        eip7702?: number;
      };
    };
  };
```

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

## **Description**

Cherry-pick of #31913 for `12.16.1`.

Creating manual PR as patch required for
`@metamask/transaction-controller`.

Patch changes are cherry-picks of
[#5600](MetaMask/core#5600),
[#5635](MetaMask/core#5635), and
[#5637](MetaMask/core#5637), built from
[patch/transaction-controller-extension-12-16-1](MetaMask/core@patch/transaction-controller-extension-12-16-0...patch/transaction-controller-extension-12-16-1).

[![Open in GitHub
Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/MetaMask/metamask-extension/pull/32023?quickstart=1)

## **Related issues**

## **Manual testing steps**

## **Screenshots/Recordings**

### **Before**

### **After**

## **Pre-merge author checklist**

- [ ] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

Cherry-pick of #31913 for `12.16.1`.

Creating manual PR as patch required for
`@metamask/transaction-controller`.

Patch changes are cherry-picks of
[#5600](MetaMask/core#5600),
[#5635](MetaMask/core#5635), and
[#5637](MetaMask/core#5637), built from
[patch/transaction-controller-extension-12-16-1](MetaMask/core@patch/transaction-controller-extension-12-16-0...patch/transaction-controller-extension-12-16-1).

[![Open in GitHub
Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/MetaMask/metamask-extension/pull/32023?quickstart=1)

- [ ] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

Use feature flags to configure the gas estimation buffers, including
support for specific chain and type-4 buffers.

```js
[FeatureFlag.GasBuffer]?: {
    /** Fallback buffer for all chains and transactions. */
    default?: number;

    /**
     * Buffer for included network RPCs only and not those added by user.
     * Takes priority over `default`.
     */
    included?: number;

    /** Buffers for specific chains. */
    perChainConfig?: {
      [chainId: Hex]: {
        /**
         * Buffer for the chain for all transactions.
         * Takes priority over non-chain `included`.
         */
        base?: number;

        /**
         * Buffer if network RPC is included and not added by user.
         * Takes priority over `base`.
         */
        included?: number;

        /**
         * Buffer for the chain for EIP-7702 / type 4 transactions only.
         * Only if `data` included and `to` matches `from`.
         * Takes priority over `included` and `base`.
         */
        eip7702?: number;
      };
    };
  };
```

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

## **Description**

Cherry-pick of #31913 for `12.17.0`.

Creating manual PR as patch required for
`@metamask/transaction-controller`.

Patch changes are cherry-picks of
[#5635](MetaMask/core#5635) and
[#5637](MetaMask/core#5637), built from
[patch/transaction-controller-extension-12-17-0](MetaMask/core@@metamask/transaction-controller@54.0.0...patch/transaction-controller-extension-12-17-0).

[![Open in GitHub
Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/MetaMask/metamask-extension/pull/32144?quickstart=1)

## **Related issues**

## **Manual testing steps**

## **Screenshots/Recordings**

### **Before**

### **After**

## **Pre-merge author checklist**

- [x] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I’ve included tests if applicable
- [x] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

## Explanation

Use feature flags to configure the gas estimation buffers, including
support for specific chain and type-4 buffers.

```js
[FeatureFlag.GasBuffer]?: {
    /** Fallback buffer for all chains and transactions. */
    default?: number;

    /**
     * Buffer for included network RPCs only and not those added by user.
     * Takes priority over `default`.
     */
    included?: number;

    /** Buffers for specific chains. */
    perChainConfig?: {
      [chainId: Hex]: {
        /**
         * Buffer for the chain for all transactions.
         * Takes priority over non-chain `included`.
         */
        base?: number;

        /**
         * Buffer if network RPC is included and not added by user.
         * Takes priority over `base`.
         */
        included?: number;

        /**
         * Buffer for the chain for EIP-7702 / type 4 transactions only.
         * Only if `data` included and `to` matches `from`.
         * Takes priority over `included` and `base`.
         */
        eip7702?: number;
      };
    };
  };
```

## References

## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes