Allow edit of model responses in the chat

Validations

• I believe this is a way to improve. I'll try to join the Continue Discord for questions
• I'm not able to find an open issue that requests the same enhancement

Problem

Hi, in conversations with LLMs it can be very useful to modify the response from the model. For instance if you want to drive the conversation towards a specific direction (otherwise LLMs tend to keep on going back to what they previously said). It makes it much easier compared to trying to prompt it perfectly from the user message.

Solution

It would be perfect if we could modify model responses in the chat the same way we can already modify user messages.

Thanks a lot for the great code assistant!