Style: Enforce braces around if blocks and loops

Using clang-tidy's `readability-braces-around-statements`.
https://clang.llvm.org/extra/clang-tidy/checks/readability-braces-around-statements.html

editor/editor_folding.cpp

@@ -132,8 +132,9 @@ void EditorFolding::save_scene_folding(const Node *p_scene, const String &p_path
 	ERR_FAIL_NULL(p_scene);
 
 	FileAccessRef file_check = FileAccess::create(FileAccess::ACCESS_RESOURCES);
-	if (!file_check->file_exists(p_path)) //This can happen when creating scene from FilesystemDock. It has path, but no file.
+	if (!file_check->file_exists(p_path)) { //This can happen when creating scene from FilesystemDock. It has path, but no file.
 		return;
+	}
 
 	Ref<ConfigFile> config;
 	config.instance();