LLM TinyMMLU Dataset Implementation

[farook-edev]

As described in the parent issue, implementation of TinyMMLU is quite complete. The only things I think might need to be done are:

• ~Load data sample by sample as needed instead of all at once.~ (not necessary)
• ~Save output tokens in processing step and do all accuracy related calculations on the accuracy side. (needs discussion)~
• ~handle instances where no answer letter is provided. (likely fail query)~ (currently being done implicitly)
• ~properly build zero-shot prompt rather than cutting input_formatted~