API needs to provide a Job class that runs the wbstack/transferbot tool: https://github.com/wbstack/transferbot for a given wiki, acquiring OAuth credentials for the target wiki on the fly. This class will then be dispatched upon request (see https://phabricator.wikimedia.org/T368021)

When the job exits, a container lifecycle hook shall be called, signalling success/failure of the operation back to API.