[Bug 37998] Wine-mono: Type.GetType("Mono.Runtime", false) is not null, confuse runtime detection code like NUnit

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=37998

--- Comment #3 from Esme Povirk  ---
This came up again with https://github.com/madewokherd/wine-mono/issues/116

System.MonoType is also commonly used for this purpose.

I came up with a plan to add a hack that hides these types specifically when
calling Type.GetType, and disable the hack by default. Once the build process
and tests work with this enabled, we can flip the default. If there are no
reported regressions, we can remove the hack and the type. Both of those should
probably be done on a major release.