Image: Use OpenImageIO for loading and saving a variety of image formats

This checkin will use OIIO to replace the image save/load code for BMP,
DDS, DPX, HDR, PNG, TGA, and TIFF.

This simplifies our build environment, reduces binary duplication,
removes large amounts of hard to maintain code, and fixes some bugs
along the way.

It should also help reduce rare differences between Blender and Cycles
which already uses OIIO for most situations. Or potentially makes them
easier to solve once discovered.

This is a continuation of the work for #101413

Pull Request: https://projects.blender.org/blender/blender/pulls/105785

tests/python/bl_imbuf_load.py

@@ -119,16 +119,12 @@ class ImBufLoadTest(ImBufTest):
         self.check("*.exr")
 
     def test_load_hdr(self):
-        self.skip_if_format_missing("HDR")
-
         self.check("*.hdr")
 
     def test_load_targa(self):
         self.check("*.tga")
 
     def test_load_tiff(self):
-        self.skip_if_format_missing("TIFF")
-
         self.check("*.tif")
 
     def test_load_jpeg(self):
@@ -141,8 +137,6 @@ class ImBufLoadTest(ImBufTest):
         self.check("*.j2c")
 
     def test_load_dpx(self):
-        self.skip_if_format_missing("CINEON")
-
         self.check("*.dpx")
 
     def test_load_cineon(self):