Dynamic Skip

[vbreuss]

I think it would be a great idea to incorporate dynamic skip, similar to https://github.com/xunit/xunit/issues/2073, by adding the following methods:

Assert.Skip(string reason);
Assert.SkipIf(bool condition, string reason);

which will both throw a SkipTestException.

The challenge will be to keep TUnit.Engine and TUnit.Assertions separate, but maybe checking for a "SkipTestException" with a fixed namespace in the Engine project?