Description of problem:

Consumer types is a placement feature which is expected to be finished early in the U cycle and when it merges, it will be ready to consume by nova. Consumption of consumer types in nova would enable us to address two non-ideal behavior changes [1] that are present when:

[quota]
count_usage_from_placement = True

The two behavior changes consuming placement consumer types would address are:

1. "doubling" of quota usage (counted on both the source and the destination) for instances in VERIFY_RESIZE state
2. "instances" quota usage being counted for instances in the ERROR state (note: historically instances, cores, and ram were counted against quota when in ERROR state but as of Train, when [quota]/count_usage_from_placement = True, cores and ram are not counted against quota when in ERROR state and only instances are still counted for ERROR state).

[1] https://docs.openstack.org/nova/train/user/quotas.html#quota-usage-from-placement