D9446: WIP: Allow to autogenerate and install categories file

[Luca Beltrame]

lbeltrame added a reviewer: fvogt.

REPOSITORY
  R240 Extra CMake Modules

REVISION DETAIL
  https://phabricator.kde.org/D9446

To: mlaurent, kfunk, lbeltrame, cgiboudeaux, dfaure, fvogt
Cc: #frameworks, #build_system