handle_events must return the sub-handler results

[ricardofunke]

Issue #, if available:
When implementing handle_transcript_event() method, one might need to return values from there, but the upper class method handle_events() doesn't return anything, which leads to the lost of the returned value in the implemented method. Thus any calls to handle_events() returns None.
Description of changes:
Added the return clause to the handle_transcript_event() call inside handle_events()

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[ricardofunke]

Sorry, I didn't test this suggestion and I just realized I put a return clause inside a for loop. My goal is to have some sort of way to return the value from this method and the called method.

Maybe something like this, I don't know:

return [await self.handle_transcript_event(event) async for event in self._transcript_result_stream if isinstance(event, TranscriptEvent)]

This worked for me

[david-oliveira-br]

@ricardofunke Maybe you should treat as a generator and use yield instead of return