feat: Improve pattern ingester tracing (backport k226)

[trevorwhitney]

Backport 80aec25 from #14707

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What this PR does / why we need it:

We had to turn off aggregated metrics in a prod cluster because the service_name label being used for __aggregated_metric__ had crazy cardinality, it was some huge JSON blob. This PR adds some more tracing and log signals to the aggregated metrics path through the pattern ingester so we can debug what's going on.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
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