[enhancement]: Add the ability to create a temporary positive/negative prompt

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Contact Details

_No response_

### What should this feature add?

In chatting interfaces like Google Gemini, there is a concept of a "temporary chat" where you are able to create a new chat that only exists for a short time:


This is mostly used for getting quick answers from the chatbot without having to fully commit to a new chat, since the temporary chat will be disregarded in a short time. I find this useful because it means it won't clutter up the new chat interface when I am asking just rudimentary questions.

This same concept should be applied to Invoke AI. There should be a button in the prompt box that allows the user to create a temporary positive or negative prompt. Anything that is typed in this temporary positive/negative prompt box should override the main prompt box, ie. the temporary prompt is the only prompt considered for the generation.

This would be extremely useful for composites, since I wouldn't have to bork my main positive/negative prompt anytime I would want to inpaint an object in the scene (that doesn't require the time, place, location, style, etc. tags). I could always have the original prompt in my back pocket to always go back to once I'm done with the inpainting job. I know that you can just copy the original prompt and paste it back in once you are done inpainting, but it's pretty clunky and sometimes I forget I copied it, or I accidentally copy another string of text which removes the original copied text. In general, I think this would be extremely useful.

### Alternatives

_No response_

### Additional Content

Mockup for the feature: