.When(...).Throws gives a CouldNotSetReturnDueToNoLastCallException

[304NotModified]

Describe the bug
This is of course a bug in the user code, as we should use Throw instead of Throws. But the exception is at least not clear

And it's confusing, IntelliSense in VS 2022 also suggest throws:

To Reproduce
See #802

Expected behaviour

• Just work
• Or give a clear error

Environment:

• NSubstitute version: 5.1
• NSubstitute.Analyzers version: c# 1.0.17
• Platform: .NET 8

Additional context

The analyzer gives a error, but that one is still a bit confusing

There are multiple options:

1. Or give a clear error
2. Or also implement Throws on WhenCalled (not sure if this is a binary breaking change?)
3. Or delegate Throws to WhenCalled.Throw - this is difficult as Throws returns a ConfiguredCall and Throw is void

[dtchepak]

I think adding Throws as an alias to Throw on WhenCalled might be the easiest way to do this (that should take precedence over the extension method). Could make as [Obsolete] with an explanation if we want to encourage the "correct" use here.