Update Llama Conversion Script to Support Llama3
# What does this PR do ?

support Llama3 model conversion.

**Collection**: [Note which collection this PR will affect]

# Changelog 
- Add specific line by line info of high level changes in this PR.

# Usage

```python
python scripts/checkpoint_converters/convert_llama_hf_to_nemo.py --input_name_or_path PATH_TO_HF_FOLDER --output_path converted_llama3_nemo.nemo

python scripts/checkpoint_converters/convert_llama_nemo_to_hf.py --input_name_or_path llama3.nemo --output_path converted_llama3_hf.bin
```

# Before your PR is "Ready for review"
**Pre checks**:
- [ ] Make sure you read and followed [Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md)
- [ ] Did you write any new necessary tests?
- [ ] Did you add or update any necessary documentation?
- [ ] Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  - [ ] Reviewer: Does the PR have correct import guards for all optional libraries?
  
**PR Type**:
- [X] New Feature
- [ ] Bugfix
- [ ] Documentation

If you haven't finished some of the above items you can still open "Draft" PR.
