Add RocBert (#20013)

* add roc_bert

* update roc_bert readme

* code style

* change name and delete unuse file

* udpate model file

* delete unuse log file

* delete tokenizer fast

* reformat code and change model file path

* add RocBertForPreTraining

* update docs

* delete wrong notes

* fix copies

* fix make repo-consistency error

* fix files are not present in the table of contents error

* change RocBert -> RoCBert

* add doc, add detail test
Co-authored-by: weiweishi <weiweishi@tencent.com>

utils/documentation_tests.txt

@@ -132,6 +132,8 @@ src/transformers/models/resnet/modeling_tf_resnet.py
 src/transformers/models/roberta/configuration_roberta.py
 src/transformers/models/roberta/modeling_roberta.py
 src/transformers/models/roberta/modeling_tf_roberta.py
+src/transformers/models/roc_bert/modeling_roc_bert.py
+src/transformers/models/roc_bert/tokenization_roc_bert.py
 src/transformers/models/segformer/modeling_segformer.py
 src/transformers/models/sew/configuration_sew.py
 src/transformers/models/sew/modeling_sew.py