Weight conversion testing and other features

[AleHD]

Work in progress. This pull requests will include the following new features:

• Extensive weight conversion testing for llama (weights2megatron -> sharding -> unsharding -> megatron2hf) verification.
• MQA support in megatron2hf, closing add GQA(MQA) support in megatron2hf conversion #24.
• Llama-hf -> megatron script, closing HF LLaMA -> megatron weight #10.
• Use verify_correctness.py with huggingface weights in addition to megatron weights (to test weights2megatron -> megatron2hf).
• Generate HuggingFace tokenizer configuration as part of megatron2hf.py, closing Generate HuggingFace tokenizer configuration as part of megatron2hf.py (weight conversion) #19.

[dumpmemory]

Can we add llama1-hf support ?