ITV's upcoming legal conspiracy thriller Fearless has added Michael Gambon to star alongside Peaky Blinders' Helen McCrory. Shooting on the six-part drama penned by Homeland writer and executive producer Patrick Harbinson, is just beginning. Mammoth Screen (Victoria, Poldark) is producing and has set further main cast including actor-comedian John Bishop, Emmy nominee Robin Weigert (Jessica Jones), Jonathan Forbes (Catastrophe), Wunmi Mosaku (Dancing on the Edge) and…