GraphQL query error reporting

[marcotc]

Motivation

Implements RFC: https://docs.google.com/document/d/1JjctLYE4a4EbtmnFixQt-TilltcSV69IAeiSGjcUL34

Capture GraphQL query errors as span events:

Changes

Added a new test scenario graphql for any tests that simply need a GraphQL request, without any special configuration.
Also added the test file tests/test_graphql.py to assert the span event behavior.

The Ruby variant currently passes tests with the changes in DataDog/dd-trace-rb#4177.

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

Addressed!