Lin Shaye is one of those character actors—like Margo Martindale and Stephen Tobolowsky—who have worked steadily for decades in a wide variety of supporting roles and they always make everything better. Even if they just appear in a few scenes, you’re always glad to see them and you wish you could see them more. With “Insidious: Chapter 3,” Shaye finally gets her “more.” Her character, veteran psychic Elise Rainier, was the most compelling figure in the first two “Insidious” movies, which were surprise, low-budget hits in 2011 and 2013. Writer and co-star Leigh Whannell, who created the series with James Wan and directs for the first time here, wisely places her front and center and gives her plenty of room to shine.