🎨 Add auto formatter

[mayankpatibandla]

Summary:

Adds black formatter and isort as pre-commit hooks to automatically format changes. These hooks have been run on every python file in the repo.

Motivation:

These auto formatters will lead to a more consistent coding style.

References (optional):

#301

Test Plan:

• Ensure all hooks run
• Ensure GitHub actions pass
• This PR only includes formatting changes so functionality should be unaffected