Add SQLAlchemy Async support to SQLFeature

[dazziedez]

Rationale

This implementation is based on my personal use case!! I'm submitting this pr in case it may be helpful to others... feel free to disregard if irrelevant..... SQLAlchemy is a pretty solid orm library, so i thought others would benefit from this as to avoid having another database connection or use a funky silly solution just for this module to use.. I can see how it could be too specific / out of scope!!!

Summary of changes made

It adds an adapter for the sqlalchemy async_sessionmaker ONLY.

Checklist

• This PR changes the jishaku module/cog codebase
  • These changes add new functionality to the module/cog
  • These changes fix an issue or bug in the module/cog
  • I have tested that these changes work on a production bot codebase
  • I have tested these changes against the CI/CD test suite
  • I have updated the documentation to reflect these changes
• This PR changes the CI/CD test suite
  • I have tested my suite changes are well-formed (all tests can be discovered)
  • These changes adjust existing test cases
  • These changes add new test cases
• This PR changes prose (such as the documentation, README or other Markdown/RST documents)
  • I have proofread my changes for grammar and spelling issues
  • I have tested that any changes regarding Markdown/RST syntax result in a well formed document