Cameron Diaz and Benji Madden’s third baby has arrived . “Cameron and I are Happy, Excited, and feeling so BLESSED to announce the birth of our third child,” the Good Charlotte member wrote via Instagram on Monday. After sharing the infant’s unique name, Nautas, the musician added, “Welcome to the world Son!! We love life with our family — our kids are healthy & happy, and we are grateful!!” Cameron Diaz (pictured above in June 2016) and Benji Madden’s third baby has arrived. Getty Images The infant is named Nautus, Madden wrote via Instagram on Monday. benjaminmadden/Instagram Madden, 47, concluded, “Having a blast, sending all our best wishes- the Madden Family.” Diaz, 53, commented on her husband’s social media upload with red heart emojis.…