By Maksym Levin and Pavel Polityuk BORODYANKA/LVIV, Ukraine (Reuters) – Russia and Ukraine agreed on Thursday to the need for humanitarian corridors to help civilians escape Moscow’s eight-day-long invasion, the first apparent progress in talks, as the United States and Britain hit more oligarchs with sanctions. Thousands are thought to have died or been wounded as the biggest attack on a European state since World War Two unfolds, creating 1 million refugees, hits to Russia’s economy and fears of wider conflict in the West unthought-of for decades. Russian forces, however, have continued to s…