Add option for category separators

It would be great to get an option in Add / edit category to add/style separators like in the screenshot.

I currently do this by adding arbitrary characters and spaces to achieve the same separator length, but that looks completely different on mobile. 

Suggest options for:
Separator style (solid / dotted / dashed)
Label alignment (left, center, right)
Label padding (distance from label to line)
Separator vertical alignment (top, bottom, center)
Separator height (pixel value)