By Elizabeth Piper LONDON (Reuters) – British politics returns to centre stage on Tuesday after the funeral of Queen Elizabeth, with Prime Minister Liz Truss signalling her priorities by flying to her first major summit and rushing out measures to try to avert an economic slump. Since the queen’s death on Sept. 8, politics – or at least the discussion of its ins and outs – has been on pause for a period of national mourning, out of respect for a monarch who reigned for 70 years. The timing of the political pause was frustrating for some in government, coming after a two-month leadership campai…