placementtracker: fix quick tiled windows not being restored correctly
There were two problems:
- Workspace interacted with the tile mode of windows before inhibiting the placement tracker, so the wrong window state was stored in the placement tracker
- Window::setQuickTileMode is unintuitive and has some undesired side effects, meant to handle quick tiling with keyboard shortcuts and by dragging the window with a mouse specifically. This commit just works around that by un-setting the tile mode first