Added ItemProcessor State Machine Definition key for State of Type (Map) (#2577)

* Added ItemProcessor State Machine Definition key for State of Type (Map) 

As per https://docs.aws.amazon.com/step-functions/latest/dg/concepts-asl-use-map-state-inline.html,  "ItemProcessor" State Machine Definition key for State of Type (Map)  is valid.

* Added ItemSelector State Machine Definition key for State of Type (Map)

Co-authored-by: Kevin DeJong <[email protected]>

---------

Co-authored-by: Kevin DeJong <[email protected]>

Author: jayasimha537

src/cfnlint/rules/resources/stepfunctions/StateMachine.py

@@ -60,6 +60,8 @@ def _check_state_json(self, def_json, state_name, path):
                 "MaxConcurrency",
                 "Iterator",
                 "ItemsPath",
+                "ItemProcessor",
+                "ItemSelector",
                 "ResultPath",
                 "ResultSelector",
                 "Retry",