[Core] Add case-insensitive String::containsn

editor/plugins/visual_shader_editor_plugin.cpp

@@ -1957,7 +1957,7 @@ void VisualShaderEditor::_update_options_menu() {
 	}
 
 	for (int i = 0; i < add_options.size(); i++) {
-		if (!use_filter || add_options[i].name.findn(filter) != -1) {
+		if (!use_filter || add_options[i].name.containsn(filter)) {
 			// port type filtering
 			if (members_output_port_type != VisualShaderNode::PORT_TYPE_MAX || members_input_port_type != VisualShaderNode::PORT_TYPE_MAX) {
 				Ref<VisualShaderNode> vsn;