Add GitHub action to format and lint code

[dyastremsky]

This pull request adds a pre-commit to run the following:

• Black for formatting Python
• Flake8 for linting Python for conformance to PEP8, PyFlakes, and circular complexity (max-line-length set to match Black's 88 default/recommended character limit; this and other settings from Black's documentation here to avoid enforcement of limit when unnecessary).
• isort for deterministically sorting and organizing Python imports
• Clang for formatting C++, C, Java, TextProto, Proto, and CUDA
• Codespell for finding common spelling mistakes

In addition, this adds these native pre-commit hooks, details here:

• check-case-conflict
• check-executables-have-shebangs
• check-merge-conflict
• check-json
• check-toml
• check-yaml
• check-shebang-scripts-are-executable
• end-of-file-fixer
• mixed-line-ending
• requirements-txt-fixer
• trailing-whitespace

To run these locally, you can go into the repo and run pip install pre-commit and pre-commit install. After that has been done once, you just need to run pre-commit run --all-files any time you want to apply them. Once installed, it should run automatically on commit for files included in a commit. To correct spelling errors found by codespell when possible, you can install codespell (pip install codespell and potentially pip install --upgrade codespell to use the toml file in the directory) and call codespell -w <path>.

This pull request also adds a GitHub action so that these are run for every pull request and push to main. The core changes are in pre-commit.yml, pre-commit-config.yaml, and pyproject.toml. The rest of the changes are the effect of applying the action to the current repo.