netdog: Add BindCarrier to bond network files

[yeazelm]

Issue number:

Closes #3425

Description of changes:
networkd will lose track of carrier for worker devices in a bond when bringing it up. This causes a delay in the bond becoming routable while the devices re-establish carrier status. This change adds BindCarrier to bond .network files which ensures networkd brings up the bond if at least one link has carrier.

Testing done:
This produces quicker boots and the bonds become routable quickly as expected:

[    2.816654] bond0: (slave enp0s17): Enslaving as a backup interface with an up link
[    2.817785] bond0: (slave enp0s16): Enslaving as a backup interface with an up link
[    3.055789] bond0: (slave enp0s17): link status definitely up, 0 Mbps full duplex
[    3.057791] bond0: (slave enp0s17): making interface the new active one
[    3.060579] bond0: active interface up!
[    3.061597] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
[    5.561715] ACPI: bus type drm_connector registered
[    6.076869] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[    6.080478] Bridge firewalling registered
[    6.242966] Initializing XFRM netlink socket
[    6.618105] fbcon: Taking over console
[    6.619157] Console: switching to colour frame buffer device 160x50
[  207.715645] bond0: (slave enp0s16): link status definitely up, 0 Mbps full duplex
[  207.717310] bond0: (slave enp0s16): making interface the new active one

The backstop message still appears, but the network is useable well before this (fetched immediately after my metal-dev instance booted and provided a login prompt:

bash-5.1# networkctl
IDX LINK    TYPE     OPERATIONAL SETUP
  1 lo      loopback carrier     unmanaged
  2 enp0s16 ether    enslaved    configured
  3 enp0s17 ether    enslaved    configured
  4 bond0   bond     routable    configured
  5 docker0 bridge   no-carrier  unmanaged

5 links listed.

Tests were also updated to ensure this change shows up in the resulting configurations.

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[yeazelm]

Updated the PR to resolve the conflict and added a commit for fixing the tests at the same time. Otherwise, the code is the same.