[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

src/transformers/models/encoder_decoder/modeling_encoder_decoder.py

@@ -194,6 +194,9 @@ class EncoderDecoderModel(PreTrainedModel):
     def get_output_embeddings(self):
         return self.decoder.get_output_embeddings()
 
+    def set_output_embeddings(self, new_embeddings):
+        return self.decoder.set_output_embeddings(new_embeddings)
+
     @classmethod
     def from_encoder_decoder_pretrained(
         cls,