Is your feature request related to a problem? Please describe.
When the state changes between empty workspace and one with open windows the unite shell close button disappears/appears from the top panel, making other elements of the top bar move back and forth.

Describe the solution you'd like
I'd like an option to not collapse the button but reserve space in the top bar even when the button is not needed (i.e. no window is open on the current workspace).

Describe alternatives you've considered
Alternatively when no window is open on a workspace, still show the close button but greyed out.

Additional context
Currently:

What I want: