Add file upload function

[ploeber]

• Add Transcriber.upload() and Transcriber.upload_async()
• support path and BinaryIO
• add deprecation warning to extras.file_from_stream.

alternative approach, to be discussed:

• or introduce new module files? Eg. aai.files.upload() (like Node SDK)

[Swimburger]

If you're going to add upload file functionality to the Transcriber, I would name it Transcriber.upload_file and Transcriber.upload_file_async, because otherwise there's no mention of what you're trying to upload.