implemented non-generic overload for Assert.ContainsSingle

[AtolagbeMuiz]

This Pull Request fixes Assert.ContainsSingle should accept non-generic collections #6732

This Implementation involves an overload being added to the Assert.ContainsSingle which allows non-generic collections like ArrayList.

Current Behaviour

Assert.ContainsSingle throws compile time error because it only accepts generic collections.

Expected Behaviour

With this Implementation, Assert.ContainsSingle will allow non-generic collection as seen below;

[AtolagbeMuiz]

@Youssef1313 do we need to hndle AssertSingleInterpolatedStringHandler for non-generic collection as well

public static object ContainsSingle(IEnumerable collection, [InterpolatedStringHandlerArgument(nameof(collection))] ref AssertSingleInterpolatedStringHandler message, [CallerArgumentExpression(nameof(collection))] string collectionExpression = "") => message.ComputeAssertion(collectionExpression);

[AtolagbeMuiz]

removed the AssertSingleInterpolatedStringHandler for non-generic implemnation based because we didnt implement if for Assert.Count as well....

@Youssef1313