Moved functions to pytorch_utils.py (#16625)

* Moved functions to pytorch_utils.py

* isort formatting

* Reverted tf changes

* isort, make fix-copies

* documentation fix

* Fixed Conv1D import

* Reverted research examples file

* backward compatibility for pytorch_utils

* missing import

* isort fix

templates/adding_a_new_model/cookiecutter-template-{{cookiecutter.modelname}}/modeling_{{cookiecutter.lowercase_modelname}}.py

@@ -43,9 +43,8 @@ from ...modeling_outputs import (
     SequenceClassifierOutput,
     TokenClassifierOutput,
 )
-from ...modeling_utils import (
-    PreTrainedModel,
-    SequenceSummary,
+from ...modeling_utils import PreTrainedModel, SequenceSummary
+from ...pytorch_utils import (
     apply_chunking_to_forward,
     find_pruneable_heads_and_indices,
     prune_linear_layer,