ParamsCallbackManager => Rename exerciseId to exerciseIdOrUrl because accept gitlab urls too

ExpressAPI/src/middlewares/ParamsCallbackManager.ts

@@ -39,7 +39,7 @@ class ParamsCallbackManager {
             staff    : true
         } ], 'assignment');
 
-        this.listenParam('exerciseId', backend, (ExerciseManager.get as GetFunction).bind(ExerciseManager), [ {
+        this.listenParam('exerciseIdOrUrl', backend, (ExerciseManager.get as GetFunction).bind(ExerciseManager), [ {
             assignment: true,
             members   : true,
             results   : true

ExpressAPI/src/routes/ExerciseRoutes.ts

@@ -72,9 +72,9 @@ class ExerciseRoutes implements RoutesManager {
     registerOnBackend(backend: Express) {
         backend.post('/assignments/:assignmentNameOrUrl/exercises', SecurityMiddleware.check(true, SecurityCheckType.ASSIGNMENT_IS_PUBLISHED), ParamsValidatorMiddleware.validate(this.exerciseValidator), this.createExercise.bind(this));
 
-        backend.get('/exercises/:exerciseId/assignment', SecurityMiddleware.check(false, SecurityCheckType.EXERCISE_SECRET), this.getAssignment.bind(this));
+        backend.get('/exercises/:exerciseIdOrUrl/assignment', SecurityMiddleware.check(false, SecurityCheckType.EXERCISE_SECRET), this.getAssignment.bind(this));
 
-        backend.post('/exercises/:exerciseId/results', SecurityMiddleware.check(false, SecurityCheckType.EXERCISE_SECRET), ParamsValidatorMiddleware.validate(this.resultValidator), this.createResult.bind(this));
+        backend.post('/exercises/:exerciseIdOrUrl/results', SecurityMiddleware.check(false, SecurityCheckType.EXERCISE_SECRET), ParamsValidatorMiddleware.validate(this.resultValidator), this.createResult.bind(this));
     }
 
     private getExerciseName(assignment: Assignment, members: Array<GitlabUser>, suffix: number): string {