systemd: import code and fix compilation errors
Fixing
src/core/.libs/libNetworkManager.a(libnm_systemd_core_la-netif-util.o): In function `net_get_persistent_name':
/builddir/build/BUILD/NetworkManager-1.47.0/src/libnm-systemd-core/sd-adapt-core/netif-util.c:74: undefined reference to `sd_device_get_property_value'
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile:11222: src/core/NetworkManager-all-sym] Error 1
make[2]: Leaving directory '/builddir/build/BUILD/NetworkManager-1.47.0'
make[2]: *** Waiting for unfinished jobs....
make[2]: Entering directory '/builddir/build/BUILD/NetworkManager-1.47.0'
The commit (script) at systemd branch will also be adjusted.
Edited by Fernando Fernández Mancera