refactor: standardize template variables (#1749)

* standardize template variables

* update eval notebooks

* handle a few more places that need to be relabeled in the notebooks

* update template variable descriptions in notebooks

* fix column renaming for toxicity notebook

* re-run hallucination eval notebook

* style notebooks

* fix llm_classify tests and change default parameter of run_relevance_eval to reflect new template defaults

* update llama index script