Add exercise to final exam

curl --location 'http://localhost:6567/api/v1/api/v1/admin/units//final-exam/exercises' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '{
    "title": "string",
    "promptMarkdown": "string",
    "difficulty": "normal",
    "language": "javascript",
    "starterCode": "string",
    "maxCpuMs": 100,
    "maxMemoryKb": 1024
}'