By Steve HollandWASHINGTON, April 1 (Reuters) - U.S. Vice President JD Vance communicated with intermediaries from Pakistan about the Iran conflict as recently as Tuesday, a person briefed on the matter told Reuters, a sign of his expanding role in efforts to broker an end to the conflict.At President Donald Trump's direction, Vance signaled privately that Trump was open to a ceasefire as long as certain U.S. demands were met, including reopening the Strait of Hormuz, the source told Reuters on...