* [AI Chat] child frame createInterfaceAPI use
This migrates the child conversation content frame to use createInterfaceApi instead of a singleton API class and a manual context data store. Context properties are marked as deprecated to facilitate a slower move.
This continues the migration of AI Chat to use createInterfaceApi, reducing the amount of overhead to call, cache and mock mojo calls and events.
Previously:
- createInterfaceApi - a browser proxy store #29601
- Introduce createInterfaceApi infrastructure to AI Chat #33688
- [AI Chat] Migrate AIChatContext to createInterfaceApi pattern #33690
- [AI Chat] Migrate ConversationContext to createInterfaceApi pattern #33689
Fixes an issue in createInterfaceApi exposed by a flakey test:
* create interface api cancels any in-progress fetches of an endpoint that is being updated manually
I noticed this can happen in tests when the test provides data but the endpoint is setup to prefetch. The prefetch resolves after the manual api.myEndpoint.update call.