Added conversation support

[o-stahl]

Overview

This pull request introduces significant enhancements to the app, focusing on both backend storage and frontend user interface improvements.

Key Changes

• Conversation History Storage: Implemented persistent storage for conversation histories using IndexedDB, facilitated by localforage to handle the database interactions seamlessly. This ensures that users can retain their chat histories across sessions, enhancing usability and engagement.
• UI/UX Enhancements: Added new UI components, including a sidebar and a dedicated conversations component, which improve the overall layout and make the application more intuitive and accessible to users.

Details

• The IndexedDB implementation uses localforage for a straightforward and robust approach to asynchronous data storage in the browser.
• UI updates include a new sidebar for better navigation and a conversations panel that enhances the chat interface, making it more engaging and easier to use.
• These changes were designed to be integrated without disrupting the existing functionalities in a major way.