Draft: genex: Add $<LINK_LIBRARY> support
This MR introduces the following artifacts:
- genex
$<LINK_LIBRARY:feature,lib...>
to enable the grouping of libraries with, for the link step, specific prefix/suffix flags and/or flag for each library. - variables
CMAKE_<lang>_LINK_USING_<feature>
andCMAKE_<lang>_LINK_USING_<feature>_SUPPORTED
to enable users to specify features used by$<LINK_LIBRARY>
genex. - target property
OVERRIDE_LINK_LIBRARY
to handle incompatible$<LINK_LIBRARY>
declarations.
Fixes: #22812 (closed), #18751 (closed), #20078 (closed), #22703 (closed)