window-manager: Ignore fullscreen requests for current state

This fixes dragging gtk4 apps with grid and/or wobbly disabled. The gtk4
toolkit sends a request for unfullscreen even though it is windowed, and
this caused wayfire to set the geometry when dragging by titlebar, which
made the window jump to an offset when grabbing the titlebar to move it.

Fixes #2507.

src/core/window-manager.cpp

@@ -244,6 +244,11 @@ void window_manager_t::tile_request(wayfire_toplevel_view view,
 void window_manager_t::fullscreen_request(wayfire_toplevel_view view,
     wf::output_t *output, bool state, std::optional<wf::point_t> ws)
 {
+    if (view->toplevel()->pending().fullscreen == state)
+    {
+        return;
+    }
+
     wf::output_t *wo = output ?: (view->get_output() ?: wf::get_core().seat->get_active_output());
     const wf::point_t workspace = ws.value_or(wo->wset()->get_current_workspace());
     wf::dassert(wo != nullptr, "Fullscreening should not happen with null output!");