Change from using the CMake package name to using the library name instead.

This handles the case of when the library name changes but the CMake package name stays the same (as different versions of Kasten do)

The metadata is versioned to allow for older builds to continue to be used.

Differential Revision: https://phabricator.kde.org/D19222
2 jobs for master
Status Job ID Name Coverage
  Build
manual #1499
docker allowed to fail manual
kdeorg/appimage-base
manual #1500
docker allowed to fail manual
kdeorg/staticweb