feat(propagation): otel baggage support

[ZStriker19]

What does this PR do?
Following the spec here: https://www.w3.org/TR/baggage/ we implement baggage propagation for the Ruby tracer
Motivation:

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Additional Notes:

How to test the change?

[github-actions]

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^{Visited at: 2025-02-11 22:38:59 UTC}

[datadog-datadog-prod-us1]

Datadog Report

Branch report: zachg/baggage_support
Commit report: 1482be0
Test service: dd-trace-rb

✅ 0 Failed, 22487 Passed, 1507 Skipped, 5m 51s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-02-13 22:28:50

Comparing candidate commit 1482be0 in PR branch zachg/baggage_support with baseline commit 20886bc in branch master.

Found 1 performance improvements and 1 performance regressions! Performance is the same for 29 metrics, 2 unstable metrics.

scenario:profiler - sample timeline=false

• 🟥 throughput [-0.541op/s; -0.532op/s] or [-8.325%; -8.193%]

scenario:tracing - Propagation - Trace Context

• 🟩 throughput [+3513.570op/s; +3603.401op/s] or [+10.178%; +10.438%]