Outlines ADM demo updates

[barry-ravichandran]

@dmjoy Here is the MR with the changes needed for the Outlines Transformers ADM to work in a demo workflow.

At the top level here are the main changes:
(1) Expose a demo parameter to differentiate between eval and demo mode.
(2) Add a new function named get_dialog_texts to be able to populate the demo UI without running inference.
(3) Add a system_ui_prompt property to be able to get the edited prompt from the demo front-end.
(4) demo_kwargs set by the demo app which controls the shuffle_choices setting and the max_tokens and rng seed value for the response generator.
(5) A modified action_choice_json_schema_untrimmed outlines prompt which removes the maxLength parameter from the default schema.
(6) Added demo dependencies as optional dependencies to pyproject.toml and regenerated the poetry.lock file.