CI: macOS w/ CTest

[ax3l]

Enable CTest on macOS for runtime tests.

Follow-up to #874

• Small enough (< few 100s of lines), otherwise it should probably be split into smaller PRs
• Tested (describe the tests in the PR description)
• Runs on GPU (basic: the code compiles and run well with the new module)
• Contains an automated test (checksum and/or comparison with theory)
• Documented: all elements (classes and their members, functions, namespaces, etc.) are documented
• Constified (All that can be const is const)
• Code is clean (no unwanted comments, )
• Style and code conventions are respected at the bottom of https://github.com/Hi-PACE/hipace
• Proper label and GitHub project, if applicable

[MaxThevenet]

MacOS is already often the most time-consuming test. Should we close this PR, and do run tests later if needed? Also, the workflow yml files have changed a bit.

[MaxThevenet]

As this would significantly increase CI time, let's close the PR for now and re-open need comes.