Workflows

[kchason]

Adds CI workflows for the following:

• pre-commit checks
• CASE validation on any .json files in the data/ directory
• Build and run the three language projects

[ajnelson-nist]

I'd prefer some of the test matrices be expanded a bit. I forget if matrix-nesting can be done precisely at the spots I suggested. I won't block the PR if you'd like to merge now.

[ajnelson-nist]

How about we merge this now and address the comments I made in follow-on PRs. They should all be straightforward if I understand the syntax and nesting right, but it might be a few round-trips with GitHub Actions.

[ajnelson-nist]

All of my comments have been or are being addressed in other PRs.