speech enhancement - return dataclass in `process` method

[krishnacpuvvada]

    I think prepare a futureproof solution and return (by option) the equivalent of a Hypothesis dataclass object. Ofc this will be some other dataclass name and content but will allow flexibility in the future. By default just return str paths, and if user requests for this dataclass, fill it with contents as needed and return.

Originally posted by @titu1994 in #5356 (comment)