Remove two classes that are not really needed and a method. We moved to
named tuples to make things simpler. Unfortunally C# does not support:

```csharp
using MyNamedTuple = (string Name, double value, bool answer);
```

But we have to live with this. Makes the namespace simpler and removes
confusion with the already present project classes that are more widely
used.

The class is not really needed. Move to a tuple, make the definition of
the group test project nicer since the dictionary initiallization makes
it cleaner.

…name namespace.

The Generator and the Factory classes are a xamarin-macios thing.
Initially, they were separated because the code that generated the bcl
tests was not inside xharness. That is not longer the case. We can merge
both classes, generalize the namespace and be more prepared to move out
of the xamarin-macios repo.