MOSCOW — Residents of rebel-held eastern Ukraine voted for leaders Sunday, taking another step toward establishing an independent enclave and exacerbating tensions between Russia and the West. Thousands of residents across war-torn eastern Ukraine lined up to give their backing to the current rebel leadership, which has been working to establish a new pro-Russian state in the southeast corner of the country. The vote, which was embraced by Russia and condemned by Western and Ukrainian leaders, will change little in terms of leadership on the ground.