Feature Request: Allow saving images generated via the API to disk

[solstice-r]

Currently, when generating an image using the SD REST API, it is not saved to the generating machine's hard drive, and only sent to the client. For logging purposes, saving the image onto the generating machine's hard drive (and maybe even allowing the client to choose the name with a JSON argument) instead of forcing the client requesting generations to do so would be a nice QOL feature.

[solstice-r]

#8287 will solve this if it is merged, waiting on AUTOMATIC1111's review...