chore: disable persistence for legacy assets controllers

[salimtb]

Stop writing Tokens, CurrencyRate, TokenRates, TokenBalances, AccountTracker, and Multichain assets/rates/balances controller state to disk so clients can rely on AssetsController instead.

Explanation

References

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 communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

---

Note

Medium Risk
Changes what asset-related state is written to disk, including user token lists and ignored assets. Clients that still depend on these controllers for persistence may lose that state on restart if they have not migrated.

Overview
Stops writing legacy assets controller state to disk so clients can rely on AssetsController instead.

Sets persist: false on state metadata for TokensController, CurrencyRateController, TokenRatesController, TokenBalancesController, AccountTrackerController, MultichainAssetsController, MultichainAssetsRatesController, and MultichainBalancesController. Persistence tests now expect empty persisted state.

^{Reviewed by Cursor Bugbot for commit f5efcc8. Bugbot is set up for automated code reviews on this repo. Configure here.}