Move windows to a new workspace (move window to workspace --new)

## I'm submitting a…

[ ] Bug

[x] Feature Request

[ ] Documentation Request

[ ] Other (Please describe in detail)

## Current Behavior
First of all apologies if this is not the place to ask this question. I've tried to reach someone in IRC but even though the channel is filled, I didn't get any answers and it doesn't have archive to check if someone eventually responded.

What I'm trying to do is to use `for_window` to open the selected window in a new empty workspace. Reading through the docs, the only options are `move, next, prev, etc` but I couldn't find a way to send the container to a new pristine workspace.

Is such feature available?

Thx in advance.