fix: allow union typing for supported bindings

[hallvictoria]

todo: support built-in collection types (list) after Bill's PR is merged

Python 3.10 and above allow for ABCMeta | _GenericAlias type hinting syntax.
(For example: event: func.EventHubEvent | List[func.EventHubEvent])

For bindings that allow List[<type>] type hints, this allows for the new syntax.

This is accomplished by:
- Adding a new method as part of the type checking process
- The new method will parse the individual types in the Union and determine if all of the types are supported
- If any of the types in the Union aren't supported, indexing will fail
- As this new method is part of an or statement in type checking, it won't affect any currently supported type hints

Bindings that can now support this syntax:
- EventHub
- Kafka
- ServiceBus

Fixes: Azure/azure-functions-python-worker#1524