By Jeremiah Hassel In a rare moment of solidarity, Prince Harry and Prince William exchanged a glance as they walked behind their grandmother’s coffin, and in that moment, two painful shared memories surfaced in fleeting moments of déjà vu. This wasn’t the first time either of them had been in the exact position they were in at the moment — just two decades earlier, they had trailed behind the coffins of two of their other relatives not once but twice, including their own mother, Princess Diana. A new groundbreaking book about King Charles III, which details his first year as King following th…