Ideas for improved window tiling

There is a number of requests to improve the half-screen tiling functionality of gnome-shell:

• Make Super-Left/Right work across multiple monitors

• 696130 Allow quarter tiling

• 665758 Add animations to snapping

• 649797 Add edge resistance when dragging windows between monitors

• 671054 Add a keybinding to move windows between monitors

• 645153 make windows resizable by window-border-drag when in half-fullscreen-snap-mode

• 709655 CSD has rounded edges even for half-maximized state

Many tiling enhancements go hand-in-hand with better multi-monitor handling.