Image gallery problems and possible improvements

[morgan55555]

1. Users can't delete selected images from gallery. Only wipe it completely.
2. If user choose to delete image from folder on server instead, gallery still trying to display those images, they appered as blank. Interface need to check for deleted images. (bug!)
3. No folders in gallery. Hovewer, ComfyUI can save in different folders by filename prefix (e.g. "cars/SDFX"), can it be used?
4. Gallery is personal, stored locally. But sometime users want to view other users art. Maybe, add switch "own/all" for images? Also, maybe we can use history instead, like gallery for current user, history for all. Why we need to show history only in "graph" view?
5. Local storage is not perfect solution. I cannot view my gallery from other devices. ComfyUI with enabled --multi-user will show user selection screen (currently without any password) and all setting will be saved per user. It's will be great for SDFX AI, for syncing workflows, galleries and other settings.