Merge topic 'exported-modules-with-headers'

2041f7c9bf cmGeneratorTarget: add the original target as a COMPILE_ONLY link
051c2110c8 Tests/CXXModules: test exporting modules which include headers

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !9469