In function does not handle enumerable parameters.

[bijington]

Describe the bug
Consider the following test:

var expression = new Expression("In(true, [delete])");

var value = expression.Evaluate(new Dictionary<string, object> { ["delete"] = new object[] { null } });

Assert.That(value, Is.False);

This will always currently fail.

Expected behavior
The assertion should be valid.

Platform (please complete the following information):

• OS: Windows/iOS
• OS Version: 10/14.5
• Version v2.4.0