Added support for Lambda lineage in X-Ray trace header

[ezhang6811]

Update: will hold off on merging this PR until we have confirmed with Lambda that they are ready for this change in all of the OTel language SDKs. Please still provide review in the meantime.

Changes

For Lambda invocations, OpenTelemetry language SDK's are expected to support Lambda Lineage in the X-Ray trace header via W3C baggage. See this Java PR for similar solution in Java.

This PR updates X-Ray Propagator to extract Lineage attribute from X-Ray trace header and add it to baggage in context, as well as inject Lineage from baggage into trace header if it exists. Updated unit tests to verify Lineage is validated and propagated as expected.

There is currently little to no public documentation on the new V2 lineage header, though it has already been utilized for Lambda invocations for a few months. The existing available documentation tends to reference the V1 lineage format, which looks something like Lineage=a87bd80c:1|68fd508a:5|c512fbe3:2 in the X-Ray trace header. This format tracks up to 16 resource IDs with their respective counters to detect recursive Lambda calls, causing size issues with trace header storage in the past. The V2 Lineage follows the format <Counter><HashedString><Counter>, i.e. Lineage=200:e65a2c4d:11. The updated algorithm only tracks a single resource, preventing the header from ever exceeding 18 characters. We've confirmed via E2E tests that this is the Lineage format actively used for Lambda calls.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[ppittle]

@AsakerMohd - given your familiarity with the code, can you also review?