load old messages

lib/controllers/from_controller.dart

@@ -0,0 +1,15 @@
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:matrix/matrix.dart";
+
+class FromController extends Notifier<String?> {
+  FromController(_);
+  @override
+  String? build() => null;
+
+  void set(String? value) => state = value;
+
+  static final provider =
+      NotifierProvider.family<FromController, String?, Room>(
+        FromController.new,
+      );
+}