Add a permission to generate ai media images

@thejimbirch Permission is currently controlled by the Image: Create new media or Create media permissions which can be granted or revoked for different roles.

I think you're asking for the ability to allow an editor to upload an image, but not be allowed to generate an AI image? Yes?

I'm not sure how much value this would add since the workaround would be there: the editor could just upload an AI generated image from another system. And then we lose out on the benefits of doing this within Drupal: e.g. having the filename note that the image is AI generated, control over providers/models, etc.