feat(backend): Question- en AnswerRepository aangemaakt.

Ook functie toegevoegd om submissies te verwijderen.

backend/src/entities/questions/answer.entity.ts

@@ -15,7 +15,7 @@ export class Answer {
     sequenceNumber!: number;
 
     @Property({type: "datetime"})
-    timestamp!: Date;
+    timestamp: Date = new Date();
 
     @Property({type: "text"})
     content!: string;

backend/src/entities/questions/question.entity.ts

@@ -20,7 +20,7 @@ export class Question {
     author!: Student;
 
     @Property({type: "datetime"})
-    timestamp!: Date;
+    timestamp: Date = new Date();
 
     @Property({type: "text"})
     content!: string;