By Stefano Rebaudo MILAN (Reuters) – Euro zone government bond yields hit fresh multi-year highs on Tuesday while spreads between core and periphery widened amid concerns about accelerated central bank monetary tightening. Yield spreads have been widening since Thursday’s European Central Bank policy meeting when the bank flagged interest rate hikes to contain high inflation but said it saw no need to create a new tool to help weaker economies cope with rising borrowing costs. Italy’s 10-year government bond yield rose 4.5 basis points (bps) after hitting its highest since December 2013 at 4.2…