cmake: Fix CMAKE_POLICY_*_CMP<N> regex and add special args to get_cmake_property
Reviewers: Framework: Syntax Highlighting, cullmann
Reviewed By: Framework: Syntax Highlighting, cullmann
Subscribers: cullmann, kwrite-devel, kde-frameworks-devel
Tags: Kate, Frameworks
Differential Revision: https://phabricator.kde.org/D25811