Feature request: Add methods for getting all entities of a certain type from state

[GuyPaddock]

The documentation indicates that state.bees should be considered internal/private and that data should be accessed from it via selector methods. In our use case, we need an entity of a specific type but don't know the ID (i.e. it's the "current user" resource, which we get via an endpoint called /jsonapi/me), so we need the ability to get all of the "current_user" entities that have been retrieved.

Unfortunately, the getEntity() method requires both a type and ID in the handle. So, for now, I'm having to write my own selector method to pull the entity directly out of state.bees.entities.