Expose API for tiling
Currently mutter doesn't expose any API for tiling capabilities except for getting a tile match and toggling the tile with keyboard actions.
In https://github.com/elementary/gala, we would like to have a little bit more API's exposed e.g:
- being able to call a function to tile a window to a side
- Get the current tile mode
- Optionally, when a window is moved to a side of the screen, enable mutter based WM's to decide what to do with that through overriding a function