Two hours: Is it enough for even a part of any person’s real life, dramatized? The biopic form practically demands failure, or at least a series of narrative compromises made under pressure from so many factions: the real-life subject, or keepers of the now-deceased subject’s estate, nervous about an unsympathetic truth or two; the streamer or studio backing the project; and the filmmakers themselves, trying to do right by the person featured in the title, while finding a shape — and the ideal performer — to make the thing work. “Shirley,” now streaming on Netflix, constitutes the latest frust…