- made system role check async

src/ClientServer/Controllers/ControllerWithDb.cs

...Server/Controllers/Core/AssessmentStatisticsController.cs

...lientServer/Controllers/Core/Exercises/PLangController.cs

...entServer/Controllers/Core/Exercises/ReleaseController.cs

...Server/Controllers/Core/Exercises/SubmissionController.cs

...ClientServer/Controllers/Core/Exercises/TagsController.cs

...ntrollers/Core/Exercises/TutorViewAssessmentController.cs

src/ClientServer/Controllers/Core/Misc/LangController.cs

...ClientServer/Controllers/Core/SystemSettingsController.cs

src/ClientServer/Controllers/Core/Users/GroupController.cs

...ientServer/Controllers/Core/Users/GroupRolesController.cs

...entServer/Controllers/Core/Users/SystemRolesController.cs

src/ClientServer/Controllers/Core/Users/UsersController.cs

...ClientServer/Controllers/dashboard/DashboardController.cs

src/ClientServer/Models/Users/SystemRolePermission.cs