* fixes#1769
* Automatically set image to ImageView if imageItem is provided.
Added a test for correct initialization of ImageView with imageItem and levelMode.
To reduce complexity, and make it easier to add more images and tests,
the images in the `test-data` repository should be merged with the main
repository. Furthermore, we can remove a lot of the subprocess work in
the image_testing.py file, as we no longer need to have it interact with
git.
The images are not the same. Images were regenerated with Qt6, and now
have proper big and little endian handling thanks to @pijyoi
Second commit is a slightly modified variant of
2e135ab282d6007b34a3854921be54d0e9efb241 authored by @pijyoi
it is to convert qimages to RGBA8888 for testing. Image
files were regenerated images for the big/little handling
Fixed issue with bogus test from test_NonUniformImage and generated a
new image
