Relocate catch2 helper macros from alib2std
It really makes no sense to have it inside alib2std component. Moved into separate tests/ folder.
From 1. 4., DockerHub introduces new very strict rate limitations on docker image pulls.
Consider changing FROM tags in dockerfiles to use altenative providers or add login step at the beginning of CI/CD job as authenticated requests aren't affected.
It really makes no sense to have it inside alib2std component. Moved into separate tests/ folder.