By Robin Emmott BRUSSELS (Reuters) – The European Union should consider sanctions on Bosnia’s autonomous Serb Republic (RS) and also withhold financial support if the Balkan country’s crisis continues to worsen, according to an internal EU document seen by Reuters. Bosnia has been going through its worst political crisis since the end of the Balkan wars of the 1990s, with Bosnian Serbs challenging state institutions as part of their longtime bid to secede and eventually join neighbouring Serbia. The internal document prepared by the EU’s foreign service for EU foreign ministers said that trave…