Notifications: Edited notifications data access objects, so as they return an object with id defined, when save{object} methods are called.
RPC: Edited NotificationsManagerMethods, so as methods with type save{object} return objects with id defined.
Revert "Notifications: Edited notifications data access objects, so as they return an object with id defined, when save{object} methods are called. RPC: Edited NotificationsManagerMethods, so as methods with type save{object} return objects with id defined."

This reverts commit e13d456713fcb8f1318b9196ca605c92a34e8717.