Update to xunit.v3 3.x prerelease

[Youssef1313]

Fixes #147

NOTE: I noticed you have some APIs in PublicAPI.Unshipped.txt but they are actually shipped and should have been moved to shipped. I left that in place. So, for the constructors that changed their signature, if originally was in Unshipped, I updated in place. And if it was originally in Shipped, I added to Unshipped with *REMOVED* prefix and added the new API.

[AArnott]

I noticed you have some APIs in PublicAPI.Unshipped.txt but they are actually shipped and should have been moved to shipped

Good point. I'll fix that.
I also note that you made several binary breaking changes by implicitly removing the default constructors on all the attributes. I'll correct that as well.

[AArnott]

Oh, I see that even xunit.v3 drops their default constructor on the attributes. I guess binary compatibility isn't a goal for xunit.v3 across major versions, so it's pointless to try to achieve on our side. I'll keep what you've done.

[AArnott]

Oh, I see that even xunit.v3 drops their default constructor on the attributes. I guess binary compatibility isn't a goal for xunit.v3 across major versions, so it's pointless to try to achieve on our side. I'll keep what you've done.

[Youssef1313]

Oh, I see that even xunit.v3 drops their default constructor on the attributes. I guess binary compatibility isn't a goal for xunit.v3 across major versions, so it's pointless to try to achieve on our side. I'll keep what you've done.

Yes. xunit.v3 is following semantic versioning now. So major release can have binary breaking changes. The binary break for removal of parameterless constructor is the primary reason why the current version of xunit.stafact cannot work with xunit.v3 3.0 prerelease. (to make it more funny, the tests are silently not discovered because of an empty catch in xunit when getting attributes, which swallows the MissingMethodException)