“Doing something great is overrated,” a cynical and embittered Mare Sheehan says at a crucial moment in HBO’s “Mare Of Easttown,” an outstanding and deeply human drama and crime procedural. “Because people expect that from you…all the time.” Played to resentful, unapologetically cantankerous perfection by Kate Winslet, Mare, a small-town Pennsylvania police detective, is making the perfect summation of her crummy life—the expectations that have haunted her and the burden of an early glory that has long faded but still defines her.