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.

BUG: 465157


(cherry picked from commit 2babccda)