TaskCancellation (#7669)

* Smol comment

* WIP, not passing ray.init

* Fixed small problem

* wip

* Pseudo interrupt things

* Basic prototype operational

* correct proc title

* Mostly done

* Cleanup

* cleaner raylet error

* Cleaning up a few loose ends

* Fixing Race Conds

* Prelim testing

* Fixing comments and adding second_check for kill

* Working_new_impl

* demo_ready

* Fixing my english

* Fixing a few problems

* Small problems

* Cleaning up

* Response to changes

* Fixing error passing

* Merged to master

* fixing lock

* Cleaning up print statements

* Format

* Fixing Unit test build failure

* mock_worker fix

* java_fix

* Canel

* Switching to Cancel

* Responding to Review

* FixFormatting

* Lease cancellation

* FInal comments?

* Moving exist check to CoreWorker

* Fix Actor Transport Test

* Fixing task manager test

* chaning clock repr

* Fix build

* fix white space

* lint fix

* Updating to medium size

* Fixing Java test compilation issue

* lengthen bad timeouts

python/ray/serialization.py

@@ -12,6 +12,7 @@ from ray.exceptions import (
     PlasmaObjectNotAvailable,
     RayTaskError,
     RayActorError,
+    RayCancellationError,
     RayWorkerError,
     UnreconstructableError,
 )
@@ -279,6 +280,8 @@ class SerializationContext:
                 return RayWorkerError()
             elif error_type == ErrorType.Value("ACTOR_DIED"):
                 return RayActorError()
+            elif error_type == ErrorType.Value("TASK_CANCELLED"):
+                return RayCancellationError()
             elif error_type == ErrorType.Value("OBJECT_UNRECONSTRUCTABLE"):
                 return UnreconstructableError(ray.ObjectID(object_id.binary()))
             else: