AT THE MOVIES, future Sex and the City star Kim Cattrall’s(right) vampy vixen rep is born howling in Porky’s. IN MUSIC,Joan Jett & the Blackhearts can afford to put a couple milliondimes in the jukebox, baby, as ”I Love Rock ‘n’ Roll” hits No. 1on the Billboard chart. in BOOKSTORES, Shel Silverstein’s ALight in the Attic blazes near the top of the Publishers Weeklybest-seller list. AND IN THE NEWS, the fledgling space shuttleprogram gets a boost as NASA monitors the Columbia’s currentcosmic voyage while announcing plans for a space station calledSpacelab.