Retrieves the content of a specific file for an application by its ID.
appId-orgId.success if successful, error if not.error if not successful.UNAUTHORIZED: The user is not authenticated or lacks sufficient permissions.FORBIDDEN: The user does not have permission to access the application.APP_NOT_FOUND: The specified application does not exist.PLAN_RESTRICTED_FEATURE: The user’s plan does not support file manager access (except for vertracloud.config).MISSING_PATH: The path query parameter was not provided.FILE_CONTENT_ERROR: Failed to retrieve the file content.