Formatron

- Bug fix: literals passed to FormatterBuilder now implements __str__ correctly

- Fix submodule imports

- Add utilities in `FormatterBuilder` to make using custom CFG easier
- Fix a bug when `JsonExtractor` is used together with `ChoiceExtractor`
- Fix readme example

- `logits_processors` first run execution time improved
- Remove `not_contain` parameter from `FormatterBuilder.str()` method
- improve huggingface integration's speed significantly

- Llama3 huggingface vocabulary is now handled correctly for non-ascii characters.
- Vllm integrations no longer crash on batch of different generated sequence length
- `logits_processors` execution time improved

- Fixed import namespace issue in `readme.md` examples
- Fixed `TODO` in `readme.md` function call examples
- Added manual reset API to integrations' `logits_processor` so users can manually reset formatter state if the generation does not complete normally
- Fixed a bug in `exllamav2` integrations so `Exllamav2Filter` can be reused across generations
- Significantly improved the speed of `formatter.mask_logits` on torch tensors