Issue #1106: Loading CMYK TIFFs with correct profile

This patch attempts to resolve the issue in #1106 (closed) (and possibly #1324 (closed)). It adds a check with gimp_color_profile_is_cmyk () to determine if the attached profile is CMYK. If so, it sets the Babl format accordingly and dereferences the profile to prevent it from being attached to the image in GIMP (thus removing an error message that currently appears). Patch tested with CMYK images generated from both Adobe Photoshop 2022 and Krita 5.0.

Implementation referenced from f200594d