Part of ENG-6657 : Migrate session creation code to shared worker
This corresponds to contentSessionCreator from OlmSessionCreatorContext. Now that the crypto store is in the shared worker we have to use non-react code to create outbound sessions. This diff adds a new method to olmAPI that handles that. On native it just calls out to the native code implementation. On web shared worker the implementation is taken from OlmSessionCreatorContext (which is going to be removed in a future diff), only modified to use the global shared worker crypto store instead of unpickling data from redux.
Depends on D11338