When there is no wrapper specified then there simply is no wrapper
which results in a no-op.

This enables ctest on Windows and fixes #1403.

time-Wrapper can still be used!

Beforehand this logic was executed in a forced addional CMake run
everytime after the specific executable was built. Now this is done
at the moment this information is needed (at building the package or
install target).

`#` denote a header when at beginning of line.