By Luc Cohen NEW YORK (Reuters) -Tom Barrack, a onetime fundraiser for former U.S. President Donald Trump, is expected to take the witness stand in his own defense next week in his trial on charges of being an illegal foreign agent for the United Arab Emirates. Barrack’s lawyer Randall Jackson said in open court on Friday that Barrack would the stand Friday afternoon. Later, prosecutor Sam Nitze said he expected to take substantial time to cross-examine the current witness, former Barrack lawyer Brady Cassis, meaning Barrack would not take the stand Friday. For defendants, testifying is potent…