Refactor cmTargetExport removing InterfaceIncludeDirecories
After the discussion in !6363 (closed) this refactors handling of the INCLUDES DESTINATION
argument for `install(TARGETS...) to allow for uniform recursive processing of exported targets and their link dependencies.
Because of this property in the cmTargetExport struct, exporting targets is not uniform: top-level ones have to be dealt with via the cmTargetExport objects, while all linked ones are cmGeneratorTarget objects. Let's pass this additional includedirectories via a special target property making handling exported targets uniform.
Topic-rename: refactor-target-export
Edited by Brad King