CMake refactoring for upcoming CI work.
Fixes for #2338 (closed) (remove confusing logging) Parts of #2337 (closed) in preparation for CI scripts add missing options CTest fixes from Davide
Change has been tested here: https://github.com/xnorpx/opus/actions/runs/375763518
If you want patches if it's easier for signoff comment let me know.
Edited by Marcus Asteborg