By Danilo Masoni and Sujata Rao MILAN/LONDON (Reuters) – Volatility soared across markets on Monday, with a gauge of potential swings in the euro-dollar exchange rate at the highest since November 2020 and a key measure of equity swings rising to the highest in more than two weeks. Markets took fright late on Friday after a U.S. warning that a Russian invasion of Ukraine could come “any day”. On Sunday the United States said Russia might create a surprise pretext for an attack. Stock markets fell heavily on Monday and Wall Street was tipped for a weaker start, while oil prices headed towards $…