[feature request] make window device dockable

[yiids]

Would be nice to be able to dock the window device in the interface. That would improve the user friendliness imo, Most of my video projects have a window device that I use as a preview window, opening a project without having to resize and position the window every time device would be nice.

[jcelerier]

One thing I've been wanting to do is to be able to replace the background of the score by the video of the currently selected node, and otherwise of the current video output. Would that work for you @yiids ?

[yiids]

Though that would look cool, Im not sure if it will be very good for productivity. my scores are often already pretty cluttered, and i dont think having my video output playing in the background will help in that sense ;) I usually end up resizing and putting the window in the bottom right on top of the object inspector panel, maybe a little preview tab there where you can select window devices?