By Emma Mackenzie After a period of working behind closed doors,King Charles has been advised he can return to public duties by his medical team and kicked off front-facing engagements with an emotional visit to a cancer centre and by attending one of his late mother Queen Elizabeth’s favourite events of the year: the Royal Windsor Horse Show. Whilst he was there, he shared a sweet moment with his niece Zara Tindall, which an expert has claimed showed the depth of their “effortless connection”. Zara – equestrian and daughter of Anne, the Princess Royal \- shared a hug with her uncle King Charl…