D7253: Add build-flatpak target if there is a flatpak recipe around

[Elvis Angelaccio]

elvisangelaccio added reviewers: apol, Frameworks.

REPOSITORY
  R240 Extra CMake Modules

REVISION DETAIL
  https://phabricator.kde.org/D7253

To: elvisangelaccio, apol, #frameworks
Cc: #frameworks, #build_system