chore: add KeyringController entropy ID selectors

[Gudahtt]

Explanation

Add selectors to the keyring-controller package for getting entropy source IDs. This is a refactor, these selectors were previously written as part of the profile-sync-controller package, but they belong with the keyring package.

References

N/A

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

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Note

Medium Risk
Changes how multi-SRP entropy IDs are resolved for auth and encrypted user storage, though behavior should match the prior HD keyring filtering; getPrimaryHdKeyringEntropySourceId’s parameter type changed for any external callers.

Overview
Moves HD keyring entropy source ID derivation from profile-sync-controller into @metamask/keyring-controller, exporting selectHdKeyringEntropySourceIds and selectPrimaryHdKeyringEntropySourceId (with unit tests) from the package public API.

AuthenticationController and UserStorageController now call those selectors on full KeyringController:getState instead of filtering keyrings locally. The profile-sync helper getPrimaryHdKeyringEntropySourceId is narrowed to a throw-on-missing wrapper around the primary selector and now takes KeyringControllerState rather than a keyrings array; getHdKeyringEntropySourceIds is removed from shared utils.

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