Get opentelemetry trace id from request headers

[kozistr]

What does this PR do?

Fixes #374

I made a simple middleware to extract OpenTelemetry context (e.g. trace id, span id) from request headers. When valid transparent info is provided, then, it'll gonna use that context to create the span (if not, it'll generate its own as it does currently).

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline,
  Pull Request section?
• Was this discussed/approved via a Github issue or the forum? Please add a link
  to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

@OlivierDehaene OR @Narsil