If the input file didn't exist at all, the TRY(MappedFile::map())
gives us a (cryptic) error message, but if it existed but wasn't an
image file, we would crash. Now we print a message instead.
This allows assigning a color profile from a .icc file to the output.
No pixel data conversion is taking place: the output will just contain
this profile, so it better matches the image data already.
This probably does strange things for CMYK jpegs, since JPEGLoader
converts those from CMYK to RGB but the ICC profile is still an CMYK
profile. The Right Fix for that is probably for JPEGLoader to consume
the profile when it does CMYK->RGB conversion and then not hand out
the profile data. (Or we could add a CMYK bitmap type.)
But most of the time, this is a progression :^)
At the moment, all it can do is read all image formats that LibGfx can
read and save to any image format that LibGfx can write (currently bmp,
png, qoi).
Currently, it drops all image metadata (including color profiles).
Over time, this could learn tricks like keeping color profiles,
converting an image to a different color profile, cropping out a part of
an image, and so on.
