Extract a full context (e.g. baggage) in aiohttp-server instrumentation

[Dr-Emann]

Description

Before, only a parent span was extracted, any other cross-cutting context extracted from the message would be dropped on the floor. Instead, attach the full context extracted for the duration of the call.

This uses the _start_internal_or_server_span helper function as used in e.g. flask.

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• [x] ran tox -e py38-test-instrumentation-aiohttp-server
• [x] ran tox -e py39-test-instrumentation-aiohttp-server
• [x] ran tox -e py310-test-instrumentation-aiohttp-server
• [x] ran tox -e py311-test-instrumentation-aiohttp-server

Does This PR Require a Core Repo Change?

• [ ] Yes. - Link to PR:
• [x] No.

Checklist:

See contributing.md for styleguide, changelog guidelines, and more.

• [x] Followed the style guidelines of this project
• [x] Changelogs have been updated
• [x] Unit tests have been added
• [ ] Documentation has been updated