[PretrainedFeatureExtractor] + Wav2Vec2FeatureExtractor, Wav2Vec2Processor, Wav2Vec2Tokenizer (#10324)

* push to show

* small improvement

* small improvement

* Update src/transformers/feature_extraction_utils.py

* Update src/transformers/feature_extraction_utils.py

* implement base

* add common tests

* make all tests pass for wav2vec2

* make padding work & add more tests

* finalize feature extractor utils

* add call method to feature extraction

* finalize feature processor

* finish tokenizer

* finish general processor design

* finish tests

* typo

* remove bogus file

* finish docstring

* add docs

* finish docs

* small fix

* correct docs

* save intermediate

* load changes

* apply changes

* apply changes to doc

* change tests

* apply surajs recommend

* final changes

* Apply suggestions from code review

* fix typo

* fix import

* correct docstring

docs/source/model_doc/wav2vec2.rst

@@ -34,7 +34,7 @@ Tips:
 
 - Wav2Vec2 is a speech model that accepts a float array corresponding to the raw waveform of the speech signal.
 - Wav2Vec2 model was trained using connectionist temporal classification (CTC) so the model output has to be decoded
-  using :class:`~transformers.Wav2Vec2Tokenizer`.
+  using :class:`~transformers.Wav2Vec2CTCTokenizer`.
 
 
 Wav2Vec2Config
@@ -44,13 +44,27 @@ Wav2Vec2Config
     :members:
 
 
-Wav2Vec2Tokenizer
+Wav2Vec2CTCTokenizer
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-.. autoclass:: transformers.Wav2Vec2Tokenizer
+.. autoclass:: transformers.Wav2Vec2CTCTokenizer
     :members: __call__, save_vocabulary
 
 
+Wav2Vec2FeatureExtractor
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. autoclass:: transformers.Wav2Vec2FeatureExtractor
+    :members: __call__
+
+
+Wav2Vec2Processor
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. autoclass:: transformers.Wav2Vec2Processor
+    :members: __call__, from_pretrained, save_pretrained, batch_decode, decode, as_target_processor
+
+
 Wav2Vec2Model
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~