Orla Kiely doesn’t hesitate when The Currency calls, asking if she’d like to talk about Paul Costelloe, whose death last Friday greatly saddened her. They had a lot in common: Irish designers of international repute, both London-based. But Costelloe was many other things to her, says Kiely: inspiration, mentor, champion, friend. “He was always very honest, but always with diplomacy and kindness,” says Kiely. “There was no pretending. He spoke freely and uncensored. He told you what he thought and what he believed and I always thought that was a quality to be admired. That was who he was — and he…