WASHINGTON (Reuters) -Federal prosecutors have opened a grand jury probe into whether former U.S. President Donald Trump mishandled classified records that ended up at his Florida residence, the New York Times reported on Thursday, citing two people briefed on the issue. Prosecutors have issued a subpoena to the National Archives and Records Administration (NARA) to obtain the documents, the report said. Authorities have also made interview requests to people who worked in the White House in Trump’s final days in office, it said. A grand jury probe suggests the Justice Department has advanced …