At this point, Liam Neeson can sleepwalk his way through a role where he plays a badass tough guy with a particular set of skills, and he pretty much does that in “Blacklight,” a by-the-numbers action thriller lacking in both action and thrills. Neeson plays Travis Block, but he might as well play Liam Neeson, since he routinely pumps out two or three of these genre exercises a year. (Neeson, Bruce Willis and Nicolas Cage are keeping this mill churning; if the three of them were to join forces in the same movie, would we all get sucked into a black hole?) Neeson’s Travis Block is a guy who doe…