[PyTorch] Refactor Resize Token Embeddings (#8880)

* fix resize tokens

* correct mobile_bert

* move embedding fix into modeling_utils.py

* refactor

* fix lm head resize

* refactor

* break lines to make sylvain happy

* add news tests

* fix typo

* improve test

* skip bart-like for now

* check if base_model = get(...) is necessary

* clean files

* improve test

* fix tests

* revert style templates

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

tests/test_modeling_blenderbot.py

@@ -128,6 +128,10 @@ class BlenderbotTesterMixin(ModelTesterMixin, unittest.TestCase):
     def test_feed_forward_chunking(self):
         pass
 
+    @unittest.skip("TODO: Decoder embeddings cannot be resized at the moment")
+    def test_resize_embeddings_untied(self):
+        pass
+
 
 @unittest.skipUnless(torch_device != "cpu", "3B test too slow on CPU.")
 @require_torch