By Alessandra Prentice and Issam Abdallah (Reuters) – Russian President Vladimir Putin alone can decide the fate of the 100,000 civilians still trapped in Ukraine’s war-torn Mariupol, Mayor Vadym Boichenko told Reuters on Thursday, saying that satellite images of a mass grave site were proof Russians were burying bodies to try to hide the death toll. Earlier Putin claimed victory in the battle for Mariupol after nearly two months of siege that has led to the most intense battles of the war and its worst humanitarian catastrophe. Under heavy bombardment, citizens who did not flee have suffered …