Now the tracking works with aggregated devices on aggregated devices.
So container with physical device where the device is put in a bond
which is the basis for a bridge is now handled correctly.
Test that adding physical devices to containers works, find that network setup
then doesn't work because there is no udev in the container to tell systemd
that the device is present.
Fixed by not depending on the device in the container.
Activate the new container test for release
Bonds, bridges and other network devices need the underlying not as
dependency when used inside the container. Because the device is already
there.
But the address configuration needs the aggregated device itself.
See #18319 for details. Starting network-online.target manually does not
work as it hangs indefinitely.
Additionally, don't treat avahi and dhcpcd special and sync their systemd units
with the respective upstream suggestion.
Systemd upstream provides targets for networking. This also includes a target network-online.target.
In this PR I remove / replace most occurrences since some of them were even wrong and could delay startup.
