v0.22.0

Larger-than-normal release, been a while since the last one because of
holidays. Contains a bunch of substantial bugfixes, alongside some other
smaller improvements.

No new features.

No breaking changes (kind of; see "Protocol changes").

Protocol changes:

- agent,plugin: Don't send ComputeUnit from plugin (#707)

Fixes:

- neonvm-runner: Fix iptables rules for traffic from localhost (#701)
- neonvm-controller: Fix runner pod cgroup cpu scaling (#702)
- neonvm-controller: Update VM resources status once the scaling phase is done (#708)
- neonvm-controller: Unify up/down memory scaling (#704)

Other changes:

- agent: Add project ID label to per VM metrics (#699)
- neonvm: Add manual QMP access (#703)
- agent: Send monitor requests in 1 CU increments (#713)
- neonvm-controller: Extract QMP commands for memory scaling (#704)

Upgrade path from v0.21.0:

- Scheduler must be upgraded before autoscaler-agent (and, if rolling
  back, rolled back after), due to protocol change in #707.
- The per-VM metrics have a new label added; this *may* inadvertently
  break certain usage.