Support default parameters

[anthonycr]

Given an interface

interface DefaultParameters {
    fun function(parameter: String = "default")
}

Mockingbird cannot transform the following code:

verify(defaultParameters) {
    defaultParameters.function()
}

This is because Mockingbird cannot "see" the value of the default parameter, and thus cannot determine what value to check for equality. In version 2.x, default parameters worked because Mockingbird did the verification inside the class itself. Since the verification is performed at the callsite, this is not supported in 3.x.