refactor: simplify favorites and mensa dashboard sections

src/app/_helpers/rxjs/mutation-observer.ts

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2023 StApps
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import {Observable} from 'rxjs';
+
+/**
+ *
+ */
+export function fromMutationObserver(
+  target: Node,
+  options?: MutationObserverInit,
+): Observable<MutationRecord[]> {
+  return new Observable(subscriber => {
+    const observer = new MutationObserver(mutations => {
+      subscriber.next(mutations);
+    });
+    observer.observe(target, options);
+    return () => {
+      observer.disconnect();
+    };
+  });
+}