FRANKFURT (Reuters) - The European Central Bank is "fully prepared" to provide even more stimulus as soon as June to support an economy that may shrink by a tenth this year due to the COVID-19 pandemic, the accounts of the bank's April meeting showed on Friday.The ECB has already unveiled a long list of measures to mitigate recession, including 1.1 trillion euros worth of bond buys and loans at deeply negative rates. Policymakers apparently fear this may not be enough.Arguing that a "V"-shaped..