perf: add some account list optimisations

[Prithpal-Sooriya]

Description

Some Account List Sheet Optimisations

• Add FlashList and valid virtualisation support.
• Move internal account list item to a separate memoized component.
• Optimise data used inside account list (narrow data selection and list items mostly dealing with primitives)

List is decent now, however clicking to open the sheet is a little slow still. Need to investigate.

Related issues

Fixes:

Manual testing steps

1. Go to this page...

Screenshots/Recordings

Before

After

Pre-merge author checklist

• [ ] I’ve followed MetaMask Contributor Docs and MetaMask Mobile 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.