By Julia Payne LAUSANNE (Reuters) -Energy and commodity markets are in shock after Russia’s invasion of Ukraine, the world’s top trading firms said on Tuesday, warning of gas and diesel shortages in Europe and economic recession if Russian flows fall further. Prices across gas, oil, metals and agricultural markets have soared since the invasion and become so volatile that companies have had to cut traded volumes owing to strained liquidity. The chief executives of four of the biggest energy traders – Vitol, Gunvor, Mercuria and Trafigura – said the gas market in particular had become dysfuncti…