When Single Tab, DnD will create a new window (Design)

[alex285]

Description

When there is a single tab open, if we Drag and Drop it, it will create a new instance. Which actually is a very convenient way to create new windows, but at the same time breaks the logic of "moving tabs", plus it breaks consistent behavior with everything else, including Terminal

Reproduce

1. Open Files
2. Have a single Tab open
3. Drag and Drop the tab

Result: A new Files window will be created
Expected: The window should be moved

Artifacts

That's a demo that shows Terminal Vs Files tabs behavior: https://youtu.be/FUEuBQbAM6o

However, this bug report is mostly a question whats the proper design here; Because again, I do like we can create new windows from a single tab!!

[jeremypw]

I think Files behaviour is more expected; also, it is the same in Code. So I think Terminal is the odd one out. But I'll flag for elementary design comment.