Add optional traceback as spanattribute for psycopg2 instrumentation

[adilbenameur]

Description

To help debug bad performance, I thought it would be useful to have the traceback of a call to a database. Especially for ORMs like Django's that make a lot of call that might not be wanted in the first place, it could help to find the code responsible for the calls.
The changes are non breaking.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I hadded tests to check that traceback would be indeed provided in the span (and not if the option is set to False).

• test_enable_traceback (line 298 in instrumentation/opentelemetry-instrumentation-dbapi/tests/test_dbapi_integration.py)
• test_disabled_traceback (line 329 in instrumentation/opentelemetry-instrumentation-dbapi/tests/test_dbapi_integration.py)

Does This PR Require a Core Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

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

• Followed the style guidelines of this project
• Changelogs have been updated (not sure there is one for psycopg2 ?)
• Unit tests have been added
• Documentation has been updated (didn't found the doc to fill but I would happy to to)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: adilbenameur / name: Adil Benameur (8f4b497)

[xrmx]

I understand the issue but it doesn't feel right to to add something ad-hoc per instrumentation

[adilbenameur]

Would it be better if the PR also add support for the other database instrumention libs ? The implementation for psycopg2 was just for my use case but I understand that the libs must be uniform.