Currently it takes a long time to compile all the tests. Each test file takes a long time to compile. I think we should reorganize how we do tests according to:

https://github.com/catchorg/Catch2/blob/ce42deb72fab2be85a862f559984580c24cb76c4/docs/slow-compiles.md

I.e., have just one main executable, and all other test files just get linked into it. This should vastly improve the recompilation time if a test gets modified, as well as the overall time to compile tests.