LONDON (Reuters) - The euro and Italian government bonds continued on Tuesday to cheer German- and French-led plans for a 500 billion euro EU coronavirus recovery fund, though stock markets were suffering from fatigue after their best day in months.There was still a sense of optimism after Monday's news that early-stage tests on a possible COVID-19 vaccine had also proved encouraging but the momentum was shifting.Europe's STOXX 600 index gave up an early rise to slip 0.4% after surging 4% in..