sd-network: drop get_ifindices

People should use rtnl for this, and then only query sd-network by the ifindices it finds.
networkd: netdev - split NetDev struct into per-kind structs

Similarly to how unit types work.
revert patch bond
Merge remote-tracking branch 'upstream/master'

resolve conflict
Conflicts:
	src/network/networkd-netdev-gperf.gperf
	src/network/networkd-netdev.c