persist member list opened status

lib/controllers/member_list_opened.dart

@@ -0,0 +1,22 @@
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:nexus/controllers/shared_prefs.dart";
+
+class MemberListOpenedController extends Notifier<bool> {
+  static const String key = "memberListOpened";
+
+  @override
+  bool build() =>
+      ref.watch(SharedPrefsController.provider).requireValue.getBool(key) ??
+      true;
+
+  Future<void> set(bool value) async {
+    final prefs = ref.watch(SharedPrefsController.provider).requireValue;
+    state = value;
+
+    prefs.setBool(key, value);
+  }
+
+  static final provider = NotifierProvider<MemberListOpenedController, bool>(
+    MemberListOpenedController.new,
+  );
+}