x11: Fix maximize animation
Window::maximize() used to be split in two halves:
- generic Window::setMaximized() and Window::maximize()
- protocol-specific Window::changeMaximize()
Window::changeMaximize() used to block all geometry updates and Window::maximize() emit "maximize mode changed" signals. With that, frameGeometryChanged came always before clientMaximizedStateChanged.
After merging Window::changeMaximize() and Window::maximize(), the order of the signals has been reversed because of RAII. Unblock geometry updates explicitly to preserve the old behavior.