feat: Add MultichainNetworkController to handle both EVM and non-EVM network and account switching

[Cal-L]

Explanation

This PR updates both the MultichainNetworkController and AccountsController to handle network switching as well as account switching. The logic handles the following logic:

• Switching accounts on AccountsController will notify MultichainNetworkController to update if the account belongs to evm vs non-evm network (MultichainNetworkController subscribes to AccountsController event)
• Switching between networks on MultichainNetworkController will notify AccountsController to update accounts based on which network the account belongs to (AccountsController subscribes to MultichainNetworkController event)

References

Fixes https://github.com/MetaMask/accounts-planning/issues/804

Changelog

@metamask/accounts-controller

• BREAKING:
  • Added MultichainNetworkSetActiveNetworkEvent to allowed events. This is used to subscribe to the setActiveNetwork event from the MultichainNetworkController and is responsible for updating selected account based on network changes (both EVM and non-EVM).

@metamask/multichain-network-controller

• ADDED:
  • Allowed actions - NetworkControllerGetStateAction | NetworkControllerSetActiveNetworkAction. The MultichainNetworkController acts as a proxy for the NetworkController and will update it based on EVM network changes.
  • Allowed events - AccountsControllerSelectedAccountChangeEvent to allowed events. This is used to subscribe to the selectedAccountChange event from the AccountsController and is responsible for updating active network based on account changes (both EVM and non-EVM).

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

[tommasini]

This looks amazing! Lets align today with the review made on the PR #5209

[mcmire]

Hello! I left some comments. I'm still trying to understand the changes introduced here. I know more changes are coming, but I am still curious why some things are being introduced here without being explicitly used, when they could be introduced later. Other than that I had some improvements we could make to the types, and some naming adjustments.

[mcmire]

@Cal-L Can you run yarn update-readme-content when you get a chance? This should add the controller to the README and update the graph there.