Moved user-service to follow folder conventions

backend-services/user-service/.gitignore

backend-services/user-service/config.js

backend-services/user-service/controllers/appController.js

backend-services/user-service/database/conn.js

backend-services/user-service/middleware/auth.js

backend-services/user-service/model/User.model.js

backend-services/user-service/package-lock.json

backend-services/user-service/package.json

backend-services/user-service/router/route.js

backend-services/user-service/server.js