There was a time when British Olympic medal winners became household names because there were so few of them. But the 67 medals at this year’s Games in Rio and 147 at the Paralympics meant that the GB medallists’ reception at Buckingham Palace was a crowded and happy event. Throughout the Commonwealth there were equally joyful celebrations. Grenada, the Bahamas, Jamaica and New Zealand won more medals per head of population than any other countries. Many of this year’s winners …