Seven years after its last instalment, the “Alien” franchise is set to get a new film in August promising to be particularly gory. Even by the standards of the films that brought us the indelible image of a deadly parasitic alien bursting out of a human chest, the first trailer for “Alien: Romulus”, which 20th Century Studios has posted on YouTube, appears to be seeking new heights of horror. “Help! Someone help me please,” cries the trailer’s first voice as we track through a dark spaceship and see streaks of blood as the voice turns to screams. At the same time, we’re told the seventh film i…