Adds support for clang-format

[ilumsden]

This PR adds a .clang-format configuration and support scripts to simplify autoformatting.

[ilumsden]

@daboehme I've added a few extra things to this PR, so I wanted to make a list of changes here:

• Adds a .clang-format configuration file to configure autoformatting and format checking of C/C++ code
  • This configuration file is designed for clang-format v16.0
• Adds the autoformat.sh script, which uses clang-format to autoformat the entire repo
• Adds Dockerfile.format and the autoformat-docker.sh script to run autoformat.sh with clang-format v16.0.6
• Adds the check-formatting.sh script, which uses clang-format to check the formatting of the entire repo
• Adds Dockerfile.check and the check-formatting-docker.sh script to run check-formatting.sh with clang-format v16.0.6
• Adds a new GitHub Action script (format-check.yml) to check C/C++ code formatting in CI
  • This script is essentially the CI version of check-formatting-docker.sh. I couldn't just use that script in the CI because docker run cannot be used in GitHub Actions.
• Adds the results of autoformatting the repo

All that's left to do in this PR is tune the .clang-format file to get the desired formatting.

[ilumsden]

To-Dos:

• Bump version of clang-format to 17.0.6
• Make function curly braces on new line
• Allow short functions on single line
• Look into function call formatting. Specifically see if indents can be fixed amount instead of with open parenthesis
• Enable AlignConsecutiveAssignments
• Look into adding spaces around operator declarations/definitions

[ilumsden]

@daboehme I've made the changes you requested. The only one I wasn't able to exactly as you wanted was the change regarding spaces around operator definitions/declarations. I was able to add spaces between e.g., operator+ and the parentheses for arguments, but I was not able to add spaces between the operator keyword and the symbol.

When you get the chance, please take a look, and let me know if there are any other tweaks you'd like.