BERLIN, Sept 3 - Voters in the eastern state of Saxony-Anhalt go to the polls on Sunday in an election where the far-right Alternative for Germany (AfD) party is hoping to win power for the first time and mark a historic shift in German politics.State Premier Sven Schulze from Chancellor Friedrich Merz's conservative Christian Democrats (CDU) says the election in Saxony-Anhalt is "a decision that will set the course for Germany."Opinion polls in the state have put support for the AfD, which wants to restrict immigration, restore ties with Russia and quit the euro, at more than 40%, 15 to...