feat: teacher get, post en delete route

backend/src/interfaces/teacher.ts

@@ -0,0 +1,36 @@
+import { Teacher } from "../entities/users/teacher.entity.js";
+
+/**
+ * Teacher Data Transfer Object
+ */
+export interface TeacherDTO {
+    username: string;
+    firstName: string;
+    lastName: string;
+    endpoints?: {
+        self: string;
+        classes: string;
+        questions: string;
+        invitations: string;
+    };
+}
+
+/**
+ * Maps a Teacher entity to a TeacherDTO
+ */
+export function mapToTeacherDTO(teacher: Teacher): TeacherDTO {
+    return {
+        username: teacher.username,
+        firstName: teacher.firstName,
+        lastName: teacher.lastName,
+    };
+}
+
+export function mapToTeacher(teacherData: TeacherDTO): Teacher {
+    const teacher = new Teacher();
+    teacher.username = teacherData.username;
+    teacher.firstName = teacherData.firstName;
+    teacher.lastName = teacherData.lastName;
+
+    return teacher;
+}