Description

Changes

• adds utilities for fetching blockedTokens from the swaps api
• disables a dest token if it's in the blockedTokens list AND if it's not the same as the src token

Related issues

Fixes: N/A

Manual testing steps

1. Go to send page, chainId=1

2. ETH -> BNB should not be possible

3. BNB -> BNB should be possible

4. BNB -> ETH should not be possible

5. BNB -> USDC should not be possible

6. BNB -> TKN should not be possible

7. Switch to a chain that's not supported by swaps

8. There should be no errors/crashes when attempting to do a simple send flow

9. Console/Network tab should have no errors regarding the blockedTokens api call

Screenshots/Recordings

Blocked dest tokens disabled:

Disable swap+send when src token is blocked:

Pre-merge author checklist

• I’ve followed MetaMask 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.