chore(wallet): improve panel performance

[onyb]

This PR contains the following perf improvements:

1. Use optimised balance scanners for ERC20 and SPL tokens, whenever possible.
2. Migrate panel to use the useGetTokenBalancesForChainIdQuery query hook.
   i. The panel no longer reads the balances from the legacy Redux store.
3. Only fetch balances for selected account and network on the main page.
   i. Similar optimisation is done for the "account assets" panel screen.
4. Prevent querying of balances on startup, and lazy-fetch it only after components that need balances have mounted.
   i. Similarly, balance refresh as a result of various panel actions have been removed.
5. Use async.mapLimit to throttle concurrent promises performing HTTP requests.
   i. This maximum number of concurrent promises allowed is 10.
6. Prevent a full refresh of balances when switching to a custom network.
   i. This is the result of a bug, but this is a good short-term solution for now.

Resolves brave/brave-browser#30772
Resolves brave/brave-browser#22714

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run lint, npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[josheleonard]

Looks good! 👍

[brave-builds]

A Storybook has been deployed to preview UI for the latest push