Handle more types (e.g. file / media) for automatic function calling

**Is your feature request related to a problem? Please describe.**
Automatic function calling does not seem to allow for a function that returns a file / media. the parser will throw an error with `Failed to parse the parameter return_value`.

**Describe the solution you'd like**
It would seem reasonable to me that the parser handles `genai.types` as return_values. for instance `genai.types.FunctionResponse` or `genai.types.FunctionResponseBlob`

**Describe alternatives you've considered**
Don't know of any alternatives