Merge topic 'cmake-gui-macos-install'

7ebad5d201 cmake-gui: Refactor installation into CMake.app/Contents on macOS
a65d986850 cmake-gui: Simplify macOS bundle version logic
91bb70cfcb Source: Factor out common parts of install layout variable loop item names

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !11376