Revert "Revert "build: Require libvirt-gconfig >= 0.2.0""

This reverts commit dbeb449bf040d6429c61bc3331bc909583172c51.
Revert "Revert "vm-configurator: Explicitly assign keyboard""

This reverts commit 28180c3f7acad00f796a8868ab74ec2201d3d173.