Fretboard diagrams: reduce empty space in the Inspector

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.4.2.9788, revision: 148e43f

There's a lot of space between the Fretboard Diagram properties and the diagram itself in the Inspector.

This could easily be reduced by a half or more, saving scolling on smaller screens. It would also be useful if the diagram in the Inspector could be reduced in scale (according to user preference), again to help reduce scrolling. Reducing the size of the above-nut symbols would also help here.