NotePropertiesRuler tweaks

[theGreatWhiteShark]

Some things in NotePropertiesRuler are not ideal yet

• dragging of a non-selected note behaves differently than dragging a (single) selected one. (For the former the cursor does not change to a dragging one and it has to be located in the same column as the note.)

  It feels weird anyway to not discard the current selection when dragging a note which is not contained in it. So, I would suggest clicking a note for dragging should discard the previous selection and selects the clicked one instead.

• dragging in NoteKey editor does not integrate well. There we have two rows: octave and key. But when selected - they are always selected in pairs - only the keys can be dragged. Instead, key and octave should be decoupled, key should be the default, but one should also be able to drag-select different octaves.

• scale of the left side of keys in NoteKey editor does not integrate well

• scale of the left side of octaves in NoteKey editor is missing