fix: add TaskQuestionsService to the DI

Author: YuriUfimtsev

HwProj.CoursesService/HwProj.CoursesService.API/Startup.cs

@@ -39,6 +39,7 @@ public void ConfigureServices(IServiceCollection services)
             services.AddScoped<ITasksService, TasksService>();
             services.AddScoped<ICourseFilterRepository, CourseFilterRepository>();
             services.AddScoped<ITaskQuestionsRepository, TaskQuestionsRepository>();
+            services.AddScoped<ITaskQuestionsService, TaskQuestionsService>();
             services.AddScoped<ICourseFilterService, CourseFilterService>();
             services.AddScoped<CourseMentorOnlyAttribute>();