The UK is set to experience the steepest slowdown in growth among G20 economies as a result of the war involving Iran, the OECD warns.The organisation now expects UK GDP to expand by just 0.7% this year, a marked downgrade from its earlier 1.2% forecast.At the same time, UK inflation is projected to rise to about 4%, up sharply from previous estimates. Global forecasts were also adjusted.While...