Feature request: custom style prompt

[rsandx]

The included styles in this node are pretty good, but there're actually endless styles, it's impossible to include all, and if you include more the list will become too long to use easily. I propose to add a custom style prompt input, so that user can use an artist style, such as "breathtaking {prompt} by Anna Dittmann," weights can also be easily added by user. This should work as long as the simple format is followed, i.e., the style contains a {prompt} placeholder, which is simple to validate. When there're values in both the selected style and custom style, the custom one should take precedence. Please consider adding this feature., which will make this node the most powerful prompt styler.