Make use of CMake module from nm-qt to search for libnm (NetworkManager library) instead
of previous NM library which has been deprecated. This new library has been introduced with
NM 1.0 which was released ~3 years ago so I assume it's not problem to require it. It also
fixes build of solid-networkstatus with NM support as it was not never enabled because NM_07
was not set.
BUG:393255