Add a regression test for extracting and injecting the parent_id under the p tracestate key

[zacharycmontoya]

Motivation

We learned that Java fails to do a correct propagation of the parent_id p when the scenarios is:

• Incoming tracestate has a p value
• A local span is generated that is a child span of the remote trace context
• The local span is injected into downstream headers

This new test asserts that the correct p value is injected downstream, which is the span-id of the local span.

Changes

Adds a new test tests/parametric/test_headers_tracecontext.py::test_tracestate_w3c_p_extract_and_inject that executes for all languages, except for Java where it is skipped due to nonconformance.

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes (if something not related to your task is failing, you can ignore it)
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner. We're working on refining the codeowners file quickly.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed, you can merge it!

🛟 #apm-shared-testing 🛟

Reviewer checklist

• If PR title starts with [<language>], double-check that only <language> is impacted by the change
• No system-tests internal is modified. Otherwise, I have the approval from R&P team
• CI is green, or failing jobs are not related to this change (and you are 100% sure about this statement)
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added (or removed)?
  • Get a review from R&P team