Store Gateway: Inconsistent error handling on series limits

[yeya24]

#6171 changed the Series request to return gRPC status code ResourceExhausted when limit is reached.

However, we didn't do the same thing for LabelValues and LabelNames request, but they will also potentially hit the series limit when matchers are specified. Now LabelNames and LabelValues returns Internal and Aborted error respectively.

https://github.com/thanos-io/thanos/blob/main/pkg/store/bucket.go#L1577
https://github.com/thanos-io/thanos/blob/main/pkg/store/bucket.go#L1765

[douglascamata]

@yeya24 nice find! We will try to get some new team members to work on this, if you don't mind. Otherwise I'm happy to use my time to fix it.

[yeya24]

We probably want to do the same for bytesLimiter also. I will probably go ahead and work on the bytesLimiter one and leave the labels one here.

[douglascamata]

Looks like with #6330 and #6325 merged we can close this, am I right, @yeya24?

[yeya24]

Yes, thanks for the reminder.