Added full SDXL style list from stable-diffusion-art.com

[frenchroasted]

1. Grouped existing styles with prefixes. The .json file is already organized by style category, but the code is designed to alphabetically sort the styles into the web UI selector. Using prefixes will retain the category groupings.
2. Added all styles from https://stable-diffusion-art.com/sdxl-styles/ The final list is inconveniently long in the web UI, but there are some interesting styles that were missing, like all the Futuristic ones. Perhaps a future version could enhance the UI with separate expandable groups to make it more convenient on the screen. Meanwhile, it's always possible to just collapse the whole list when you're not using it.

[shao-shuai]

upvote for this PR, for a temporary fix, I just copy and relace the json file, thanks Aaron!

[Versace69]

Upvote here also!!

I will add to be able to load multiple JSON files:

1. Load all styles of all JSON files in the extension folder,
2. Show all styles but separate by JSON file,
3. Be able to expand/collapse all different JSON file in the txt2img and img2img view.

This will avoid the need to switch the JSON filename and Reload UI when need a style from another file.
Also, this will avoid to have a too long style list.

Thanks.

[slnc]

For anyone wondering, this updated version has 104 styles (for Batch count).

[bamit99]

Can you please check my update? I have added capability to pick multiple JSONs and then choose the one of your liking.