Improve CI and test coverage

[srmainwaring]

Follow up to #85:

1. Resolve issues in the tests disabled in:

• [ ] CGAL_TEST
• [ ] EigenFFTW_TEST
• [ ] WaveSimulationFFT2_TEST
• [ ] WaveSimulation_TEST

2. Change the macOS Monterey CI workflow

• [x] Only run on a PR (as it is very slow to install dependencies on the macOS runner)
• [ ] Consider removing the caching, and run a complete install each time (may be faster)
• [ ] Or - refine re-linking stage - only running the force relink on the packages that are reinstalled.
• [ ] Move build and test commands back into the main workflow yaml file from bash scripts

3. Add static checks

4. Add coverage checks