cmake-based ports: add cmake.out_of_source yes/no

[mojca (Mojca Miklavec)]

Following #33259 and r134128 it would be nice if maintainers of ports using the cmake PortGroup would add the following line to their ports

cmake.out_of_source yes

and test whether the ports still compile fine (no need for a revbump). Some ports already use out-of-source builds, so those ports would need a minor clean-up.

If the port doesn't work that way, please add an explicit

cmake.out_of_source no

with a short comment (and possibly file an upstream bug report).

Once all the ports are tested, this would become the default behaviour and the line (setting yes) will be removed from the ports.