By Andy Bruce LONDON (Reuters) – The surprise split vote behind the Bank of England’s interest rate hike last week, which was too small for almost half its officials, threatens to obscure the British central bank’s intentions and potentially hurt the economy. Some BoE watchers say emerging evidence of division among policymakers over how to respond to inflation could sow confusion about its reaction function – the way investors and the public can expect a central bank to respond to economic developments. The BoE has already been accused of mixed messaging after wrong-footing investors who expe…