feat: Add mm portfolio api - token search controller

[Bigshmow]

Explanation

This is the introduction of metamask portfolio api's token search in the core monorepo.
This will return values from Moralis intended to provide search functionality coming soon to the metamask mobile app.

References

MMPD-1504
MMPD-1526

Changelog

@metamask/token-search-discovery-controller

• ADDED: TokenSearchDiscoveryController which fetches token search results from the metamask portfolio api

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've highlighted breaking changes using the "BREAKING" category above as appropriate
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

[mcmire]

Hello! I see that you may have used create-package to create this controller — great! I wanted to let you know that when it comes to controllers in particular, there is a standard way that we have been trying to build them. We have some example controllers that you can take a look at to understand the general patterns: https://github.com/MetaMask/core/tree/main/examples/example-controllers. We also have some guidelines here as well: https://github.com/MetaMask/core/blob/main/docs/writing-controllers.md.

The "GasPricesController" in the examples might be a good controller to copy. In addition I think it would be good if we could encapsulate the network call in a service class. This is a pattern that we don't have enough documentation on, unfortunately, but you can see a good example in remote-feature-flag-controller here: https://github.com/MetaMask/core/tree/main/packages/remote-feature-flag-controller/src/client-config-api-service. Essentially, this pattern allows us to retry failed requests easily and gracefully handle when the API goes down so we don't hammer the API when we don't need to.

[Bigshmow]

Thanks for the review @mcmire , I really appreciate it! I'll work on these changes and additions asap.

[Bigshmow]

@mcmire I think we're good on refactors per your comments, and test coverage is at 100%, but the linter is angry at new warnings being introduced (not from anything we worked on here though).

Do we need to address those linter warnings separately, before this PR can be merged?