By Pawel Florkiewicz and Anita Komuves MEDYKA, Poland/BEREGSURANY, Hungary (Reuters) -Refugees fleeing Russia’s invasion of Ukraine poured across its western borders on the third day of fighting on Saturday, with more than 100,000 reaching Poland so far, many making the final stretch of their journeys to safety on foot. As Russian forces pounded Ukrainian cities including the capital Kyiv with artillery and cruise missiles, fearful families thronged European Union borders hoping to enter Poland, Slovakia, Romania and Hungary. Ukrainians already safely in the European Union waited anxiously at …