Decouple RenderingServer from as much of the codebase as possible

Notably decouples it from:
- AccessibilityServer
- DisplayServer
- Viewport
- Window

editor/script/script_editor_base.cpp

@@ -39,6 +39,7 @@
 #include "scene/gui/menu_button.h"
 #include "scene/gui/rich_text_label.h"
 #include "scene/gui/split_container.h"
+#include "servers/display/display_server.h"
 
 void ScriptEditorBase::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("name_changed"));