Move some models to candle-transformers so that it's easier to re-use. (#794)

* Move some models to candle-transformers so that they can be shared.

* Also move falcon.

* Move Llama.

* Move whisper (partial).

candle-examples/examples/bigcode/main.rs

@@ -7,8 +7,7 @@ extern crate accelerate_src;
 use anyhow::{Error as E, Result};
 use clap::Parser;
 
-mod model;
-use model::{Config, GPTBigCode};
+use candle_transformers::models::bigcode::{Config, GPTBigCode};
 
 use candle::{DType, Device, Tensor};
 use candle_nn::VarBuilder;