Migrate inference to llama_batch and llama_decode api (#795)

* Add low-level batching notebook

* fix: tokenization of special characters: (#850)

It should behave like llama.cpp, where most out of the box usages
treat special characters accordingly

* Update CHANGELOG

* Cleanup

* Fix runner label

* Update notebook

* Use llama_decode and batch api

* Support logits_all parameter

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Co-authored-by: Antoine Lizee <antoine.lizee@gmail.com>