Lists all CIFF Focal Length tag identifiers.

Values:

IGMDTAG_ID_CIFF_FOCAL_LENGTH_LENGTH	Focal length.
IGMDTAG_ID_CIFF_FOCAL_LENGTH_PLANE_XSIZE	Focal plane X size.
IGMDTAG_ID_CIFF_FOCAL_LENGTH_PLANE_YSIZE	Focal plane Y size.