Support mysql8 and bump version to 0.22.1-tw-0.8.

[JohnZZGithub]

1. Upgrade mysql connector to 8.2.0
2. Add thrift generated files under twitter-extensions to avoid hard dependency to thrift 0.10.0 in run time.
3. Fix python script to be comptaible with python3*
4. Bump version to 0.22.1-tw-0.8.

Fixes #XXXX.

Description

Fixed the bug ...

Renamed the class ...

Added a forbidden-apis entry ...

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This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths.
• added integration tests.
• been tested in a test Druid cluster.

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Key changed/added classes in this PR

• MyFoo
• OurBar
• TheirBaz