By Suban Abdulla LONDON (Reuters) – The downturn in Britain’s housing market eased last month as falling mortgage rates pushed up demand, according to a survey published by the Royal Institution of Chartered Surveyors on Thursday that added to signs of stabilisation in the sector. The RICS measure of new buyer enquiries rose to a net balance of -3 in December – its least negative since April 2022 – from November’s -13. A gauge of agreed home sales increased to -6 in December, the highest reading since March 2022. Tarrant Parsons, senior economist at RICS, said lower borrowing costs in financia…