[factored out from bug 914199]
Chrome version: 70.0.3538.110 (Official Build) (64-bit)
OS: Chrome

Repro steps:
1. Run weston-terminal (most likely any other Wayland application will do).
2. Press Ctrl-Z in the terminal you launched weston-terminal from.
3. Try to move/resize/minimize/close the weston-terminal window.

Expected: the window owned by an application that - thanks to the SIGTSTP - no longer responds should still be movable, minimizable and closable.

Actual: the window owned by the application that no longer responds can neither be moved, nor resized, nor minimized, nor closed. Even from the overview, where a X button is provided, the window cannot be closed.

Suggested solution: provide _some_ means of window management even for non-responding windows, e.g. via the dock (where weston-terminal doesn't even get an icon).