Use Array for node configuration warnings

Previously, the warnings were passed as a string and delimitation of which were hard coded at each implementation.

scene/main/shader_globals_override.h

@@ -58,7 +58,7 @@ protected:
 	static void _bind_methods();
 
 public:
-	String get_configuration_warning() const override;
+	TypedArray<String> get_configuration_warnings() const override;
 
 	ShaderGlobalsOverride();
 };