To be more consistent between genex and variables as well as
the forecomming LINK_GROUP genex, rename variable *_LINK_USING_<FEATURE>*
in *_LINK_LIBRARY_USING_<FEATURE>*
This generator expression offers the capability, for the link step, to
decorate libraries with prefix/suffix flags and/or adding any specific flag for each
library.
Fixes: #22812, #18751, #20078, #22703