Add ctest test registration

[mathisloge]

It would be really nice if a command like catch_discover_tests https://github.com/catchorg/Catch2/blob/74fcff6e5b190fb833a231b7f7c1829e3c3ac54d/extras/Catch.cmake#L158C10-L158C30 would be provided.

E.g. IDE's like clion or visual studio code have a test section to only execute special suites instead of always the whole executable.

[WardBrian]

I've built a rudamentary version of this for my own usages today that might be useful as a baseline:
https://gist.github.com/WardBrian/1932c302fca3f9bf46563bf7a0666af9

It relies on you wiring up argc and argv to the .run function from main