Description of the new feature/enhancement

Padding can be represented in 3 formats:

• # --> all sides
• #,# --> width & height
• #,#,#,# --> left, top, right, & bottom

The Settings UI currently represents the padding as a single slider. If the settings.json has a more complex representation (i.e. format 2 or 3), we present the last value in the slider. It would be nice if we had support for the other formats too.

Proposed technical implementation details (optional)

#8764 has a lengthy discussion on this issue. I've decided to move that here for easier tracking.

@mdtauk has proposed some neat designs here.