Usage Ping: Query recorded Prometheus metrics

What does this MR do?

Depends on: omnibus-gitlab!4343 (merged) Replaces: !34936 (closed)

We recently introduced Usage Ping functionality that pulls data from the bundled Omnibus Prometheus (assuming it is running.) This is now documented here: https://docs.gitlab.com/ee/development/telemetry/usage_ping.html#prometheus-queries

In the initial iteration that shipped with 13.1, these queries were sent to Prometheus ad-hoc, i.e. queries that contained potentially long-term aggregations were evaluated at query time. They were also fairly complex at times.

In this MR we implement the client-side counterpart for omnibus-gitlab!4343 (merged), i.e. we are now sending much simpler PromQL queries that will fetch weekly averages of the recorded metrics. This makes for a faster and more stable contract between client and server.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done
• Tested manually in GCK container
• Tested in Omnibus container

References

• Epic: &3209
• Use recording rules: #218548 (closed)