Sort by exif timestamp in get_animal_photos before copying

[max-mapper]

At this point https://github.com/OxyCompBio/Oxy-Megadetector/blob/edde72217cad134fa230e66915931f1de6998c3e/get_animal_photos.py#L44

we should add another loop that sorts the photos using EXIF so the first and last photo are correct