Roll back to previous UI with the settings sidebar on the right

The new UI has some drawbacks:

• Additional Settings options in the left sidebar leaves less space for chats and folders.

• Settings button under the message field in the chat makes it necessary to close it to use the chat

• Switching between text and image mode or adjusting settings takes more clicks

• It was great when the model and reasoning mode toggle were visible

• New settings pop-ups are small

• etc.