reduce local state service class size

[ssube]

The local state service is becoming a god class, when it should focus on creating and stepping the world state.

• the this.focus and this.transfer helpers should be extracted
  • they each have a few methods
  • they both mutate the world state (this.focus sets state.focus.{actor,room} and this.transfer moves entities)
  • this.focus has state of its own: the output buffer for the current step (this.buffer)
• the createActor/createItem/createRoom methods should be extracted
  • they share a focus on creating an entity from its template
  • they use the Counter, Random, and Template services
• the gatherPortals/populatePortals/populateRoom methods should be extracted
  • they share a focus on adding new portals to existing rooms
  • they need the Template service + everything createRoom uses