replaced account data singleton with a session model

lib/state/app/modules/capabilities/bloc/capabilities_cubit.dart

@@ -5,7 +5,7 @@ import 'package:hydrated_bloc/hydrated_bloc.dart';
 import '../../../../../api/demo/data/demo_capabilities.dart';
 import '../../../../../api/demo/demo_mode.dart';
 import '../../../../../api/marianumconnect/queries/get_capabilities/get_capabilities.dart';
-import '../../../../../model/account_data.dart';
+import '../../../../../session/session_manager.dart';
 import 'capabilities_state.dart';
 
 /// Holds the current user's mobile capability flags. Hydrated so the last
@@ -35,12 +35,12 @@ class CapabilitiesCubit extends HydratedCubit<CapabilitiesState> {
       emit(DemoCapabilities.state());
       return;
     }
-    final epoch = AccountData().sessionEpoch;
+    final epoch = SessionManager().sessionEpoch;
     try {
       final response = await GetCapabilities().run();
       // A slow answer for the previous account must not decide the modules
       // of the next one.
-      if (!AccountData().isCurrentSession(epoch)) return;
+      if (!SessionManager().isCurrentSession(epoch)) return;
       emit(
         CapabilitiesState(
           viewForeignTimetables: response.viewForeignTimetables,