Add SeamlessM4T v2 (#27779)

* add working convertion script

* first non-working version of modeling code

* update modeling code (working)

* make style

* make fix-copies

* add config docstrings

* add config to ignore docstrings formatage due to unconventional markdown

* fix copies

* fix generation num_return_sequences

* enrich docs

* add and fix tests beside integration tests

* update integration tests

* update repo id

* add tie weights and make style

* correct naming in .md

* fix imports and so on

* correct docstrings

* fix fp16 speech forward

* fix speechencoder attention

* make style

* fix copied from

* rename SeamlessM4Tv2-v2 to SeamlessM4Tv2

* Apply suggestions on configuration

Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* remove useless public models

* fix private models + better naming for T2U models

* clean speech encoder relative position embeddings

* refactor chunk attention

* add docstrings to chunk attention method

* improve naming and docstrings

* rename some attention variables + add temperature sampling in T2U model

* rename DOCSTRINGS variable names

* make style + remove 2 useless config parameters

* enrich model card

* remove any attention_head reference + fix temperature in T2U

* new fmt and make style

* Apply suggestions from code review

Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* rename spkr_id->speaker_id and change docstrings of get_char_input_ids

* simplify v2attention

* make style

* Update seamless_m4t_v2.md

* update code and tests with last update

* update repo ids

* fill article name, abstract andauthors

* update not_doctested and slow_doc tests

---------

Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

README.md

@@ -466,6 +466,7 @@ Current number of checkpoints: ![](https://img.shields.io/endpoint?url=https://h
 1. **[RoFormer](https://huggingface.co/docs/transformers/model_doc/roformer)** (from ZhuiyiTechnology), released together with the paper [RoFormer: Enhanced Transformer with Rotary Position Embedding](https://arxiv.org/abs/2104.09864) by Jianlin Su and Yu Lu and Shengfeng Pan and Bo Wen and Yunfeng Liu.
 1. **[RWKV](https://huggingface.co/docs/transformers/model_doc/rwkv)** (from Bo Peng), released on [this repo](https://github.com/BlinkDL/RWKV-LM) by Bo Peng.
 1. **[SeamlessM4T](https://huggingface.co/docs/transformers/model_doc/seamless_m4t)** (from Meta AI) released with the paper [SeamlessM4T — Massively Multilingual & Multimodal Machine Translation](https://dl.fbaipublicfiles.com/seamless/seamless_m4t_paper.pdf) by the Seamless Communication team.
+1. **[SeamlessM4Tv2](https://huggingface.co/docs/transformers/main/model_doc/seamless_m4t_v2)** (from <FILL INSTITUTION>) released with the paper [<FILL PAPER TITLE>](<FILL ARKIV LINK>) by <FILL AUTHORS>.
 1. **[SegFormer](https://huggingface.co/docs/transformers/model_doc/segformer)** (from NVIDIA) released with the paper [SegFormer: Simple and Efficient Design for Semantic Segmentation with Transformers](https://arxiv.org/abs/2105.15203) by Enze Xie, Wenhai Wang, Zhiding Yu, Anima Anandkumar, Jose M. Alvarez, Ping Luo.
 1. **[Segment Anything](https://huggingface.co/docs/transformers/model_doc/sam)** (from Meta AI) released with the paper [Segment Anything](https://arxiv.org/pdf/2304.02643v1.pdf) by Alexander Kirillov, Eric Mintun, Nikhila Ravi, Hanzi Mao, Chloe Rolland, Laura Gustafson, Tete Xiao, Spencer Whitehead, Alex Berg, Wan-Yen Lo, Piotr Dollar, Ross Girshick.
 1. **[SEW](https://huggingface.co/docs/transformers/model_doc/sew)** (from ASAPP) released with the paper [Performance-Efficiency Trade-offs in Unsupervised Pre-training for Speech Recognition](https://arxiv.org/abs/2109.06870) by Felix Wu, Kwangyoun Kim, Jing Pan, Kyu Han, Kilian Q. Weinberger, Yoav Artzi.