Introduce a Duo AI Features Menu to Allow Users to Access AI Features and Customizations

Problem to solve

There is currently no way for users to interact with AI features for customization.

Proposal

We propose introducing a space within the Gitlab menu for users to interact directly with AI features, to include model selection and RAG implementation. AI features could either be nested within Settings as it's own menu option, or included in General settings as an expandable menu option.

Option 1 -- Directly within Settings:

Option 2 -- An expandable menu within Settings > General:

For our MVP, the Duo AI Features should allow access to our self-hosted configurations and toggle between available models for a given feature / use case. User should be prompted to input necessary fields for configuration.