fix: Various manual fixes/tweaks in preparation for clang-tidy PR

[dbanks12]

Description

Blocks #393

• Adds clang-format/clang-tidy/clangd configuration files and a helper script for tidying
• Fixes code that actually breaks clang-tidy (auto-fixes lead to compilation errors without these manual fixes)

The purpose of this intermediate/separate PR is that individuals can merge just this patch into their branches so they can then run clang-tidy successfully to relieve some pains when trying to merge the larger refactor which is coming next.

Checklist:

• I have reviewed my diff in github, line by line.
• Every change is related to the PR description.
• I have linked this pull request to the issue(s) that it resolves.
• There are no unexpected formatting changes, superfluous debug logs, or commented-out code.
• The branch has been merged or rebased against the head of its merge target.
• I'm happy for the PR to be merged at the reviewer's next convenience.

[ludamad]

LGTM (so far)

[dbanks12]

Thanks @ludamad. Just flagged it as ready after pushing the actual clang-format/clang-tidy/clangd configurations and the script for tidying. This PR fixes code that actually breaks clang-tidy (auto-fixes lead to compilation errors without these manual fixes).

The purpose of this intermediate/separate PR is that you/others can merge just this patch into your branches so you can then run clang-tidy successfully to relieve some pains when trying to merge the larger refactor which is coming next.