Fix tests

[ProbablePrime]

https://github.com/Yellow-Dog-Man/FreeImage/tree/main/Wrapper/FreeImage.NET/cs/UnitTest exists and is quite extensive, but I can't get that to compile locally.

[ProbablePrime]

There's info here: https://github.com/Yellow-Dog-Man/FreeImage/blob/main/Wrapper/FreeImage.NET/cs/UnitTest/NUnit.txt

But I wonder if we could modernize the test harness to be...easier!

[Kim-SSi]

Where can I get the contents of the UnitTestData\Images folder so that I can run the tests?
I am trying to see if I can compile and test the FreeImage.NET project on VS2022 and sdk style projects, with NUnit before attempting to update the NUnit version.

[ProbablePrime]

I dont know, https://github.com/Yellow-Dog-Man/FreeImage/blob/main/Wrapper/FreeImage.NET/cs/Content.txt lists the reason we dont have it.

[Kim-SSi]

I was able to find the UnitTestData folder by looking through the FreeImage SF discussions.
I have created a pull request with the files #16