add support for default generics on declaration and extensions

[uittorio]

No description provided.

[uittorio]

Now we are using the type(generics)declarations instead of the typeArguments to loop through the generics

interface Interface<A> { // A is the typeDeclaration
 prop: A;
}
createMock<Interface<string>>(); // string is the typeArgument

with the typeDeclaration its easier to store default generics if not provided

Example

interface InterfaceB<T> {
 bProp: T;
}
interface InterfaceA<A = string> extends B { 
 prop: A;
}

createMock<InterfaceA>();

When we check interface B we didn't really store the default value in A so it was not possible to auto default to string.

The code now is checking against typeDeclaration and if the generic has been provided in typeArguments. If not it will store the default generic.

I hope it make sense