Add Ability to Call an OpenAI Assistant

[reidellawfirm]

Describe the feature you'd like to request

OpenAI API has an Assistant option where you can call a specifically trained or fine tuned model using your API and the Assistant ID.

Just like how NC Assistant 2.0 gives the user the ability to choose the model, it would be another powerful option to be able to choose an OpenAI Assistant to handle specialized tasks from within NC.

https://platform.openai.com/docs/assistants/overview

Describe the solution you'd like

Add an option to select and call a specific OpenAI Assistant within NextCloud Assistant 2.0.

Describe alternatives you've considered

Not sure, could always just continue to use openAI Assistants separately from NextCloud.