Description

The responses for the API Calls to aggregator metadata, block list and blocked tokens are not currently mocked on any tests, however the requests happen in the majority of tests. These request return a json back that takes in some occasions more than 1 second to return.

With this PR we mock these responses, so they are immediate, mitigating any possible delay and flakiness due to real live requests.

Note: We are returning the data, since it's been seen that if we return just an empty json, some tests fail as they rely on some data from that requests

Related issues

Fixes: https://github.com/MetaMask/MetaMask-planning/issues/2637

Manual testing steps

1. All tests should continue to pass in ci
2. Check screenshots with the real API requests and slow responses

Screenshots/Recordings

Before

See slow responses for the 3 API requests happening in tests:

• blocklist: 1.20s

• aggregator metadata: 644ms

• includeBlockedTokens: 664ms

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• 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 format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). 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.