Implement support for SurpriseMe button of ImageCreator inside ImageGen

[polkovnikov]

There is SurpriseMe button in ImageCreator.

It generates some very interesting text of suggestion (prompt) and pastes it into Edit box.

Then you click Create and this prompt is generated into image.

Would be great if you implement this surprise me text inside your ImageGen.

I suggest you inside ImageGen to just retrieve text of suggestion, without generation of image itself, afterwards using your ImageGen.ImageGenAsync() I'll create image by myself. In other words only text of a suggested image prompt is needed to be retrieved.