Their identities have been a well-guarded secret, known only to their high-powered lawyers and a handful of House lawmakers and staff. But now Fox News has learned the names of the self-described Benghazi “whistleblowers” who are set to testify before a widely anticipated congressional hearing on Wednesday. Appearing before the House Oversight and Government Reform Committee will be three career State Department officials: Gregory N. Hicks, the deputy chief of mission at the U.S. Embassy in Libya at the time of the Benghazi terrorist attacks; Mark I. Thompson, a former Marine and now the deputy coordinator for Operations in the...