Rename GH1866 test, fix invalid char test, fix equality assertion order

[HebaruSan]

Problems

• The ZipValid_ContainsFilenameWithBadChars_NoException test is failing on Windows:

  1) Failed : Tests.Core.Cache.ZipValid_ContainsFilenameWithBadChars_NoException
    Expected string length 128 but was 27. Strings differ at index 0.
    Expected: "Error in step EntryHeader for GameData/FlagPack/Flags/Weyland..."
    But was:  "Illegal characters in path."
    -----------^
     at Tests.Core.Cache.ZipValid_ContainsFilenameWithBadChars_NoException() in C:\Users\User\github\CKAN\Tests\Core\Cache.cs:line 202
  

• The above error message has swapped the expected and actual values of the string

• The GH1866 test does not have a meaningful name. Every time I see it, I wonder what it does. It's hard to maintain it correctly when we are guessing about its purpose.

Causes

• I think ZipValid's error format has changed over time, and the test has an old value
• This test and a few others have the parameters to Assert.AreEqual in the wrong order, with the actual value first and the expected value second

Changes

• The invalid chars test is updated to use the current error messgae, so it will succeed on Windows
• The parameters of all Assert.AreEqual calls are expected first, actual second
• The GH1866 test is moved to Tests.GUI.ModList.InstallAndSortByCompat_WithAnyCompat_NoCrash, based on descriptions in Consistent crash when installing up updating any mod #1803, CKAN Error in Regards to Sorting #1875, Fix issue where CKAN would crash after installing mods if you are sorting by KSP version. #1866, and Fix GUI exceptions when installing/uninstalling after sorting by KSP max version #1882
  • It is now self-contained in one function rather than distributed around an entire class (private variables become locals, all steps in sequence)
  • I have attempted to organize the code into Arrange / Act / Assert sections

I might self-review this, since it's just tests and shouldn't affect users.

[DasSkelett]

Yup, the name of the test was weird. On the upside, you still knew exactly where to look for more information ^^
But the links do the job even better.

[techman83]

As the one who likely named the test 💯