Add support for AZ-separated quotas

[VoigtS]

This implementation handles the introduction of resource topologies. This allows the handling of synchronizing AZ-aware and AZ-separated quotas with the backend.
The plugins will check if a liquid provides a valid toplogy. Invalid AZ's that are detected during scrapes will be rejected. Scraped AZ-separated quota will be included into the backend_quota column that resides in the project_az_resources table. From limes quota will then be synced with the backend if necessary. The backend_quota values will then be updated to the calculated quota values.

Things to note:
* The AZ key sorting in the uitlity functions might be able to be improved.
* MatchLiquidReportToTopology might collect the errors for all resources instead of failing at the first mismatch.
* SetQuota required a new type to support passing through the AZ-aware qutoas to the backend. We might have to adjust the naming of the structure and its contents.

TODOS:

• Adjust the algorithm to not provide base quota in any for az-separated resources. (Requires additional agreement on how to approach this topic.) -> The base quota value will now be provided to all AZs if the topology is AZSeparated.
• Cleanup steps involving ResourceBehavior.CommitmentIsAZAware

[coveralls]

coverage: 79.325% (+0.3%) from 78.993%
when pulling 8e72ed5 on resource_topology
into f0beb49 on master.

[majewsky]

We're getting there. A few more nitpicks, and here's a big thing on top: I don't know how to flag this on a specific line, so I'm going to write it here. If the code works the same as in my head, we will have a neverending series of useless quota syncs on resources with AZSeparatedResourceTopology. As per the spec, these resources should have ResourceUsageReport.Quota == nil (i.e. no total quota should be reported), which means that project_resources.backend_quota will be empty. ACPQ currently always fills project_resources.quota for the resources that it operates on, so on the resource level, we always have quota != backend_quota and therefore a quota sync is forced during each ACPQ run.

My gut feeling is that ACPQ should just not fill project_resources.quota for AZSeparateResourceTopology resources. (The absence of the overall quota could then also be a trigger for the UI to hide the region-wide quota/usage bar.) But I have not finished thinking about whether that will induce corner cases elsewhere.

[VoigtS]

We're getting there. A few more nitpicks, and here's a big thing on top: I don't know how to flag this on a specific line, so I'm going to write it here. If the code works the same as in my head, we will have a neverending series of useless quota syncs on resources with AZSeparatedResourceTopology. As per the spec, these resources should have ResourceUsageReport.Quota == nil (i.e. no total quota should be reported), which means that project_resources.backend_quota will be empty. ACPQ currently always fills project_resources.quota for the resources that it operates on, so on the resource level, we always have quota != backend_quota and therefore a quota sync is forced during each ACPQ run.

My gut feeling is that ACPQ should just not fill project_resources.quota for AZSeparateResourceTopology resources. (The absence of the overall quota could then also be a trigger for the UI to hide the region-wide quota/usage bar.) But I have not finished thinking about whether that will induce corner cases elsewhere.

I did not know that it is intended for the liquid to return a nil value if it has the AZ separated toplogy. I included a skip for setting the ACPQ quota and provided an explanation for it.

[majewsky]

I have pushed a few nitpick fixes. Also, there is one last bigger thing:

[majewsky]

Awesome, thanks!