ddtrace/tracer: support reading statsd port from tracer

[hannahkm]

What does this PR do?

This PR fixes the bug where the statsd port could not be read from the tracer by placing statsd into the expected format.

Motivation

The issue was reported by [link issue]. This PR follows up on the work on [link PR].

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.

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[pr-commenter]

Benchmarks

Benchmark execution time: 2024-10-16 22:01:43

Comparing candidate commit baba093 in PR branch hannah/fix-statsd-port with baseline commit 51abc7b in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 59 metrics, 0 unstable metrics.