Is your feature request related to a problem? Please describe.

Add the ability to optionally configure a TTS voice per model. I have many types of Models on my current instance of OpenWeb UI, I'd like to select different default voices for each.

Describe the solution you'd like

• Now that Models in OpenWeb UI are seperated a bit from Modelfiles, an optional field for TTS voice could be added.
• If that voice isn't present in the TTS configs with the config endpoint is checked, then it could default to whatever the system wide default voice is

Describe alternatives you've considered
None

Additional context
This will be useful for my current usecase of making a series of educational AI persona impersonating real historical figures, I would like to give each a different voice.