Getting On

dvr this HBO, Sunday, Nov. 23, 10:30 p.m. For some reason, Getting On, the genius half-hour comedy about an enormously dysfunctional geriatric unit of a Long Beach hospital, is barely on anyone’s radar. Put it on yours. Nurse Dawn (Alex Borstein) is meek, desperately lonely, and competent; Nurse Didi (Reno 911’s Niecy Nash) is loud-mouthed…