Add QKeySequence to VirtualDesktopManager::addAction overload
There are four usages of this overload, two of them are for the intentionally disabled "Switch to Next/Previous Desktop" actions and the rest are for "Switch One Desktop to X" actions. Due to the order they were added, an empty keybind was set as the default and the actual keybind is never enabled.
Now there's a QKeySequence argument to this overload, so an unexpected empty keybind is never added. The two usages of addAction that depend on this empty keybind behavior now pass in an empty QKeySequence.
(cherry picked from commit e3982892)