The new MIT high-rise is easily picked out from the other buildings in Cambridge’s burgeoning tech and life-sciences hub of Kendall Square. From the Boston side of the Charles River, its copper-toned sheathing catches the eye: glinting in the sunlight, it appears to be subtly shifting. But though the 29-story building stands out, it has a less-than-distinctive name, referred to by the client, the Massachusetts Institute of Technology (MIT), simply as “Site 4.”