Adds scripts, Dockerfiles, and GitHub Actions CI for checking formatting and autoformatting

[ilumsden]

Since I know there's been some issues with formatting (mostly due to my VSCode being stupid), I put together this PR to provide some new tools to help us with code formatting. This PR is heavily based on LLNL/Caliper#605, which I put together for the same reason.

This PR adds several scripts to the repo (all can be found in scripts/formatting/):

• check-formatting.sh: uses clang-format to check if the files in src/ and include/ are formatted correctly
• autoformat.sh: uses clang-format to autoformat the files in src/ and include/
• Dockerfile.check: a Dockerfile that runs check-formatting.sh with clang-format v17.0.6
• Dockerfile.format: a Dockerfile that runs autoformat.sh with clang-format v17.0.6
• check-formatting-docker.sh: a script that builds and runs Dockerfile.check
• autoformat-docker.sh: a script that builds and runs Dockerfile.format

Additionally, this PR adds a new GitHub Actions workflow to check if code is formatted correctly. This script is essentially just a GitHub CI version of Dockerfile.check.

Finally, this PR adds the results of autoformatting the repo.

[ilumsden]

• Add newline to end of each file
• Enforce ordering of includes
• Tweak formatting to preserve include groups and sort within each group
• Update docs to state that includes should be placed in newline-separated groups, which external groups (e.g., for C++ Standard Library and external tools) coming before internal groups
• Merge Dockerfiles into hierarchical Dockerfile (note: figure out how to run a specific tag for this type of Dockerfile)
  • This file shows how to do it for compose: https://github.com/hariharan-devarajan/hpc-aio/blob/dev/compose-dev.yaml. Need to figure out how to do this via CLI

[hariharan-devarajan]

Lets address the comments we made during meeting.

[ilumsden]

@hariharan-devarajan all the requested changes to this PR are complete.