It was not supposed to end like this – not with recriminations, resignations and now multiple legal actions. When Fallon & Byrne opened the doors of its flagship branch in the south Dublin suburb of Rathmines, it was designed to be a template for further expansion of the high-end brand.   Stretching to more than 10,000 square feet, it included a restaurant and sprawling food haul. In January, it unceremoniously pulled down the shutters for the last time, claiming it as not financially viable. Days later two of its-cofounders, the former newspaper editor Fiona McHugh and her husband Paul Byrne,…