Fix peer tags configuration

[ichinaski]

What does this PR do?

Upon reading the info response from the Agent, we must store the peer_tags internally, which are used for Client-Stats computation.

Motivation

Client-Side Stats require peer tags aggregation. Agent e2e tests revealed that these were missing.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

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[datadog-datadog-prod-us1]

Datadog Report

Branch report: ichinaski/fix-peer-tags-config
Commit report: 226fdbc
Test service: dd-trace-go

✅ 0 Failed, 5216 Passed, 72 Skipped, 2m 31.71s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-01-31 12:22:07

Comparing candidate commit f31e3aa in PR branch ichinaski/fix-peer-tags-config with baseline commit ddfe2d4 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 58 metrics, 1 unstable metrics.