Switch to ExceptionGroup & add notes to Exceptions

[ArBridgeman]

Summary

In #313, we added two Exception classes to handle simultaneous multiple exceptions.
In Python 3.11, new features were added to Exceptions that might further improve what we've done & adhere to the common Python standards:

• https://peps.python.org/pep-0654/
• https://peps.python.org/pep-0678/
• https://docs.python.org/3/tutorial/errors.html#enriching-exceptions-with-notes
• https://docs.python.org/3/library/exceptions.html#ExceptionGroup

As Python 3.10 has an EOL slated for 2026, it'd be nice to look further into these options & potentially refactor what we've created for it. This should be assessed as to whether this brings value to the customer or not; it's thought that by adhering to a Pythonic standard that this would be an improvement and help with readability.