feat(backend): Controller en route voor het aanmaken van leerobjecten aangemaakt.

backend/package.json

@@ -31,6 +31,7 @@
         "cross-env": "^7.0.3",
         "dotenv": "^16.4.7",
         "express": "^5.0.1",
+        "express-fileupload": "^1.5.1",
         "express-jwt": "^8.5.1",
         "gift-pegjs": "^1.0.2",
         "isomorphic-dompurify": "^2.22.0",
@@ -51,6 +52,7 @@
         "@mikro-orm/cli": "6.4.12",
         "@types/cors": "^2.8.17",
         "@types/express": "^5.0.0",
+        "@types/express-fileupload": "^1.5.1",
         "@types/js-yaml": "^4.0.9",
         "@types/node": "^22.13.4",
         "@types/response-time": "^2.3.8",