effects/desktopgrid: Fix grid's size and scale w.r.t. row/column spacing
effects/desktopgrid: Replace PlasmaCore.Units.largeSpacing with gridUnit
It's broken and equal to a grid unit, all existing usages must ported
one way or another. Using smallSpacing * 2
(the intended value of
largeSpacing) results in a gap that is too narrow to be consistent when
scaled down between multiple desktops.
effects/desktopgrid: Fix grid's size and scale w.r.t. row/column spacing
This patch makes grid actually account for the spacing, so that when fully shown it won't cut off bottom or right edge of desktops. It can be easily seen with a wallpaper that has visible features on the edges such as borders, or by settings rowSpacing & columnSpacing to an absurdly high value.