* do cmake_minimum_required as first thing, as recommended
* bump KF to 5.37, first release with Kirigami (Qt 5.7 matching min dep)
* use KF5_MIN_VERSION also with ECM
* include KDE CMake settings as first
* remove unused cmake includes
* remove duplicated enable_testing()
* use correct KDEInstallDirs variables
- Add a new static library "validator_lib" covering the "validators" namespace in C++
- Introduce the Base32Validator to perform input field validation with fixup support