Description of the new feature/enhancement

Simply put, I would like to be able to take a single pane and either transform it into a tab, or add it as a pane of a different tab.
In my opinion this is useful when a specific tab gets overcrowded with panes, and gets cumbersome.
You could close the panes you want to move and reopen new ones in a different tab, but then you lose output of previous commands, environment changes you made, etc.

As for how this might appear to the user, I think it would have to be a drag & drop kind of thing for the use case of moving the pane to an existing tab (Also allowing to rearrange panes in the same tab which would be nice). Keyboard shortcuts might work too, but I think it'll make it hard to reach the exact arrangement of tabs.