Metavoice - first cut (#1717)

* Add the metavoice transformer.

* Sketch the speaker-encoder module.

* Adding to the metavoice model.

* Start adding the metavoice example.

* Get some logits out.

* Load the second stage model.

* Get the second step to run.

* Tweak the example.

* Add encodec tilting.

* Glue the different bits together.

* Fix a shape issue.

* Use a constant.

* BPE tokenization.

* Add a warning.

candle-transformers/src/models/mod.rs

@@ -18,6 +18,7 @@ pub mod llama2_c;
 pub mod llama2_c_weights;
 pub mod mamba;
 pub mod marian;
+pub mod metavoice;
 pub mod mistral;
 pub mod mixformer;
 pub mod mixtral;