workspace,window: don't elevate windows during electric border tiling / maximizing
Instead, move the outline below the window, so that the visual order of things stays the same. This also fixes a visual glitch, where the outline is visible for a moment after maximization, and is above the no-longer-elevated window
(cherry picked from commit b2ff4654)
Co-authored-by: Xaver Hugl xaver.hugl@gmail.com