Function upload_file_to_storage 

async fn upload_file_to_storage(
    conn: &mut PgConnection,
    path: &Path,
    file_name: &str,
    mime_type: &str,
    file: GenericPayload,
    file_store: &dyn FileStore,
    uploader: Option<Uuid>,
) -> Result<Uuid, ControllerError>