Remove actor handle IDs (#5889)

* Remove actor handle ID from main ActorHandle constructor

* Set the actor caller ID when calling submit task instead of in the actor handle

* Remove ActorHandle::Fork, remove actor handle ID from protobuf

* Make inner actor handle const, remove new_actor_handles

* Move caller ID into the common task spec, start refactoring raylet

* Some fixes for forking actor handles

* Store ActorHandle state in CoreWorker, only expose actor ID to Python

* Remove some unused fields

* lint

* doc

* fix merge

* Remove ActorHandleID from python/cpp

* doc

* Fix core worker test

* Move actor table subscription to CoreWorker, reset actor handles on actor failure

* lint

* Remove GCS client from direct actor

* fix tests

* Fix

* Fix tests for raylet codepath

* Fix local mode

* Fix multithreaded test

* Fix AsyncSubscribe issue...

* doc

* fix serve

* Revert bazel

python/ray/worker.py

@@ -867,7 +867,9 @@ class Worker(object):
         # TODO(rkn): It would be preferable for actor creation tasks to share
         # more of the code path with regular task execution.
         if task.is_actor_creation_task():
+            # TODO: Remove Worker.actor_id and just use CoreWorker.GetActorId.
             self.actor_id = task.actor_creation_id()
+            self.core_worker.set_actor_id(task.actor_creation_id())
             self.actor_creation_task_id = task.task_id()
             actor_class = self.function_actor_manager.load_actor_class(
                 job_id, function_descriptor)