Add the SNAC audio tokenizer. (#2869)

* Add the SNAC audio tokenizer.

* More snac.

* Again more snac.

* Add some example code for snac.

* Get the weights to load.

* Add to the snac model.

* Fixes.

* Get round-tripping to work.

* Save/load code files.

* Clippy fix.

* Fmt fix.

candle-transformers/src/models/dac.rs

@@ -330,6 +330,7 @@ impl ResidualVectorQuantizer {
         Ok(Self { quantizers })
     }
 
+    #[allow(clippy::wrong_self_convention)]
     pub fn from_codes(&self, codes: &Tensor) -> Result<Tensor> {
         let mut sum = None;
         for (idx, quantizer) in self.quantizers.iter().enumerate() {