- added support for test points and external checkers

src/ClientServer/Config/Constants.cs

...ollers/Core/CustomProjects/EditCustomProjectController.cs

...xerciseAfterSolution/DoExerciseAfterSolutionController.cs

...Server/Controllers/Core/Exercises/DoExerciseController.cs

...er/Controllers/Core/Exercises/ExerciseEditorController.cs

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

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

src/ClientServer/Controllers/Core/Init.cs

...lientServer/Controllers/Core/Testing/TestingController.cs

.../Migrations/20210525142456_TestAchievedPoints.Designer.cs

...entServer/Migrations/20210525142456_TestAchievedPoints.cs

src/ClientServer/Migrations/YapexDbContextModelSnapshot.cs

...stomProjects/CustomProjectTestWithSolutionAsTestResult.cs

...AfterSolutions/CustomTestWithAfterSolutionAsTestResult.cs

...cises/AfterSolutions/TestWithAfterSolutionAsTestResult.cs

...ises/Solution/CustomTestWithSingleSolutionAsTestResult.cs

.../Exercises/Solution/TestWithSingleSolutionAsTestResult.cs

src/ClientServer/Models/Exercises/Tests/Test.cs

src/ClientServer/Models/Interfaces/AllTest.cs

src/ClientServer/Models/Interfaces/ITestResult.cs