[pipeline]add pipeline policy and bert forward (#4130)

* add pipeline policy and bert forward to be done

* add bertmodel pipeline forward and make tests

* add Bert_Policy and test for policy

* update formatting

* update formatting

* update the code

* fix bugs

* fix name confilt

tests/test_pipeline/test_stage_manager.py

@@ -21,7 +21,7 @@ def check_stage_manager():
         1: [0, 1],
         2: [2, 3],
         3: [2, 3],
-    }
+    }   
     pg_mesh = ProcessGroupMesh(DP_SIZE, PP_SIZE)
     stage_manager = PipelineStageManager(pg_mesh, PP_DIM)
     rank = dist.get_rank()