function findExternalOrigin(moduleGraph, issuer) {
  if (!_.isNil(issuer) && _.startsWith(issuer.rawRequest, './')) {
    return findExternalOrigin(moduleGraph, getIssuerCompat(moduleGraph, issuer));
  }
  return issuer;
}
Find the original module that required the transient dependency. Returns
undefined if the module is a first level dependency.
@param {Object} moduleGraph - Webpack module graph
@param {Object} issuer - Module issuer