Multiple layouts active at same time

[tomasforsman]

Provide a description of the new feature / enhancement

I suggest that two grids could be active at the same time letting you use shift to drag windows into grid1 and shift+alt to drag windows into grid2. That would work well with shift+ctrl and shift+alt+ctrl to drag it into a combination of spaces in either grid as well.

One way this could be used is to have your usual grid together with a smaller grid where you do use ctrl for more control. Having a smaller grid is great for control but gets annoying when you want to place things into your main areas but having them both active at once would be great.

This is not a duplicate of #1411 since it's not about switching between grids but rather having them active at the same time.

An alternative way would be to have two types of elements in the grid where the secondary spaces only gets activated when you press ctrl.