compositor: Configurable behavior when window to be focused conflicts with fullscreen (#12033)

Renames `misc:new_window_takes_over_fullscreen` into
`misc:on_focus_under_fullscreen` and implements the following behavior:

- By default, when a tiling window is being focused on a workspace where
  a fullscreen/maximized window exists, respect
  the `misc:on_focus_under_fullscreen` config variable.

src/xwayland/XWM.cpp

@@ -20,6 +20,7 @@
 #include "../managers/ANRManager.hpp"
 #include "../protocols/XWaylandShell.hpp"
 #include "../protocols/core/Compositor.hpp"
+#include "../desktop/state/FocusState.hpp"
 using Hyprutils::Memory::CUniquePointer;
 
 using namespace Hyprutils::OS;
@@ -1037,7 +1038,7 @@ void CXWM::activateSurface(SP<CXWaylandSurface> surf, bool activate) {
     if ((surf == m_focusedSurface && activate) || (surf && surf->m_overrideRedirect))
         return;
 
-    if (!surf || (!activate && g_pCompositor->m_lastWindow && !g_pCompositor->m_lastWindow->m_isX11)) {
+    if (!surf || (!activate && Desktop::focusState()->window() && !Desktop::focusState()->window()->m_isX11)) {
         setActiveWindow(XCB_WINDOW_NONE);
         focusWindow(nullptr);
     } else {