Merged requested to merge gk/qqc2-desktop-style:spacingfixes into master
- In Menu.qml: Do not consider invisible menu items when evaluating whether to make space for icons or checkboxes.
- In MenuSeparator.qml: Only add space for menu separators if they are visible, otherwise set the height to 0.
|The list view makes space for a separator and checkbox that are hidden||The list view only makes space for what's visible|
|This is a followup to !135 (merged)|