Image Generation/Character Expressions: auto add expression into image generation prompt

[Kaiten10]

There could be a checkbox in the Image Generation extension: "Auto insert character expression (needs Character Expression extension enabled)" which will analyse the expression from the message using the local CE extension and automatically inserts it into the prompt.

e.g.: prompt prefix + message + [joy | anger| grief | surprise | etc.]

I think this will make image generations more responsive and interactive, especially when we use the "Generate Image" button in the chat. Sometimes the message is just dialogue and doesn't reflect the character's expression, so we have to manually add it in the prompt. This should streamline that process.