[SVLS-4298] Java upstream sqs trace context propagation

[joeyzhao2018]

What does this PR do?

This is python's version of the same logic done in the NodeJS layer PR DataDog/datadog-lambda-js#511

Motivation

JAVA lambda would put trace context information in the AWSTracerHeader inside the message.attributes
This PR extract that so that JAVA Lambda => sqs => python lambda would show as one connected trace.

Additional Notes

I refrained from refactoring too much of the code logic in this PR. But I plan to do some refactoring in a following PR. This is because the refactoring would focus more on the general structure of the extractors. Therefore not very relevant to the java upstream case here.

Testing Guidelines

Added unittest case using a java upstream example payload.
Manually tested in a real lambda setup:

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog
• This PR passes the integration tests (ask a Datadog member to run the tests)

[duncanista]

LGTM – left a non-blocking nit.

Looking forward for the refactor 🙏🏽 lmk if you need help there!