Merge topic 'cpack-path-simplify'

023720e10a cpack: Simplify config file selection
cc3c603061 cpack: Simplify package directory selection logic
a9ad70de76 Source: Avoid using CollapseFullPath just to get parent directory

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !9294