Xcode: Restore support for standalone IMPORTED_LOCATION_<CONFIG>
In !8758 (merged) we broke support
for IMPORTED_LOCATION_<CONFIG>
without IMPORTED_CONFIGURATIONS
.
Previously it worked if the importing project's configurations match the
set of IMPORTED_LOCATION_<CONFIG>
properties set. Fix that case.
Fixes: #25506 (closed)
Issue: #25515
Backport: release
Edited by Brad King