…ect configuration (#11062)

## Summary

This is a follow-up to #10984 that
implements configuration resolution for editor configuration. By 'editor
configuration', I'm referring to the client settings that correspond to
Ruff configuration/options, like `preview`, `select`, and so on. These
will be combined with 'project configuration' (configuration taken from
project files such as `pyproject.toml`) to generate the final linter and
formatter settings used by `RuffSettings`. Editor configuration takes
priority over project configuration.

In a follow-up pull request, I'll implement a new client setting that
allows project configuration to override editor configuration, as per
[this issue](astral-sh/ruff-vscode#425).

## Review guide

The first commit, e38966d, is just
doing re-arrangement so that we can pass the right things to
`RuffSettings::resolve`. The actual resolution logic is in the second
commit, 0eec9ee. It might help to look
at these comments individually since the diff is rather messy.

## Test Plan

For the settings to show up in VS Code, you'll need to checkout this
branch: astral-sh/ruff-vscode#456.

To test that the resolution for a specific setting works as expected,
run through the following scenarios, setting it in project and editor
configuration as needed:

| Set in project configuration? | Set in editor configuration? |
Expected Outcome |

|-------------------------------|--------------------------------------------------|------------------------------------------------------------------------------------------|
| No | No | The editor should behave as if the setting was set to its
default value. |
| Yes | No | The editor should behave as if the setting was set to the
value in project configuration. |
| No | Yes | The editor should behave as if the setting was set to the
value in editor configuration. |
| Yes | Yes (but distinctive from project configuration) | The editor
should behave as if the setting was set to the value in editor
configuration. |

An exception to this is `extendSelect`, which does not have an analog in
TOML configuration. Instead, you should verify that `extendSelect`
amends the `select` setting. If `select` is set in both editor and
project configuration, `extendSelect` will only append to the `select`
value in editor configuration, so make sure to un-set it there if you're
testing `extendSelect` with `select` in project configuration.

## Summary

This is a follow-up to astral-sh/ruff#10984,
which implemented support for common Ruff configuration options in
client settings. This PR exposes these new settings in the extension
configuration.

These settings are different from other extension settings, because they
don't have default values. Instead, if the user does not set them, they
will be sent as `null`, and the server will use project configuration
instead.

At the moment, `ruff server` does not actually resolve these settings
yet - settings resolution is introduced in
astral-sh/ruff#11062, which means that you'll
need to work from that branch to test this PR (and vice-versa).

## Test Plan

See the test plan in astral-sh/ruff#11062.

## Summary

This is a follow-up to astral-sh/ruff#10984,
which implemented support for common Ruff configuration options in
client settings. This PR exposes these new settings in the extension
configuration.

These settings are different from other extension settings, because they
don't have default values. Instead, if the user does not set them, they
will be sent as `null`, and the server will use project configuration
instead.

At the moment, `ruff server` does not actually resolve these settings
yet - settings resolution is introduced in
astral-sh/ruff#11062, which means that you'll
need to work from that branch to test this PR (and vice-versa).

## Test Plan

See the test plan in astral-sh/ruff#11062.