WASHINGTON, Feb 28 (Reuters) — A highly anticipated meeting between Ukrainian President Volodymyr Zelenskiy and former U.S. President Donald Trump exploded into a diplomatic fiasco on Friday, as tensions over the Russia-Ukraine conflict reached a public boiling point in front of a global audience at the White House. Zelenskiy had entered the Oval Office expecting to bolster support and dissuade the U.S. from siding with Russian President Vladimir Putin, who spearheaded the ongoing assault on