More customizability for the new tab screen

[stefdev1]

Basically, every extension can pack a widget and you can drag and resize them on the new tab page like on Android. Also let us move and resize everything on the home screen for that matter.

For Android and iOS, on portrait mode the widgets will not be draggable or resizable and will be on an infinite tape. On landscape it will be like desktop.

For example, uBlock Origin could ship a widget that shows how many ads it blocks.