Improve Exif tag support and performance

[ezwelty]

We currently use piexif for reading image metadata. This works fine, but faster (and more actively maintained) libraries may be faster and/or be able to parse manufacturer-specific maker notes.

Alternatives to consider include:

• GDAL, since we are using it already (https://gdal.org/drivers/raster/jpeg.html#exif-and-gps-tags)
• pyexiv2 (https://github.com/LeoHsiao1/pyexiv2)
• exif-py (https://github.com/ianare/exif-py)
• PyExifTool (https://github.com/smarnach/pyexiftool) or another Python wrapper of exiftool

Todo

• Add support for Exif(path: pathlib.Path) (only Exif(path: str) is currently supported)
• Add properties to access additional tags useful for camera system forensics
  • Camera serial number: BodySerialNumber, CameraSerialNumber, maker notes (e.g. Canon.SerialNumber, Nikon3.SerialNumber)
  • Lens serial number: LensSerialNumber
  • Lens make: LensMake
  • Lens model: LensModel
  • Lens info (focal range, aperture range, etc): LensSpecification, LensInfo, maker notes (e.g. Canon.LensModel, Canon.LensInfo)
  • Shutter count: maker notes (e.g. Nikon3.ImageCount)
  • Frame number: file name (e.g. 'IMG_1234.JPG'), maker notes (e.g. Canon.FileNumber, NikonFi.FileNumber, NikonFi.DirectoryNumber)
  • GPS coordinates: GPSLatitudeRef, GPSLatitude, GPSLongitudeRef, GPSLongitude, GPSAltitudeRef, GPSAltitude, GPSMapDatum
  • GPS datetime: GPSDateStamp, GPSTimeStamp