Introduce a shared library to access telephony APIs for 3rd party C++/Qt applications
A proposal to provide a KF5-style shared library (for example, similar to PulseAudioQt) with CMake files to simplify integration with 3rd party Qt/C++ applications like KDE Connect.
The integration is already possible with a small static library from the kde-telephony-meta subproject, which provides ready-to-use marshaling methods for existing custom types of the API. While it still makes sense to provide a shared library with ready-to-use API without a need to generate interfaces directly with XML files via the qt5_add_dbus_interface
method.
The result could also be reused in the kde-telephony-plugin-declarative subproject (which already provides a shared QML API).