Fix unmarshaling of nested DS Dictionary

[aparajit-pratap]

Purpose

Fix issue with passing nested DesignScript.Builtin Dictionary to ZT node accepting generic Dictionary (Dictionary<string, object>) as argument.
JIRA link: https://jira.autodesk.com/browse/QNTM-4917

Zero touch node definitions used in this example:

 public static Dictionary<string, int> ReturnDictionary()
        {
            var dictionary = new Dictionary<string, int>();
            dictionary.Add("A", 1);
            dictionary.Add("B", 2);
            dictionary.Add("C", 3);
            dictionary.Add("D", 4);
            return dictionary;
        }
 [MultiReturn(new string[] {"H", "G", "F", "E"})]
        public static Dictionary<string, object> ReturnNestedDictionary()
        {
            var dict = ReturnDictionary();
            var dictionary = new Dictionary<string, object>();
            dictionary.Add("E", 1);
            dictionary.Add("F", 2);
            dictionary.Add("G", dict);
            dictionary.Add("H", false);
            return dictionary;
        }
 public static Dictionary<string, object> ReturnArbitraryDictionary()
        {
            var dict = ReturnDictionary();
            var dictionary = new Dictionary<string, object>();
            dictionary.Add("E", 1);
            dictionary.Add("F", new Dummy());
            dictionary.Add("G", dict);
            dictionary.Add("H", false);
            dictionary.Add("I", new object[] {1, 2, 3, 4, new DummyCollection()});

            return dictionary;
        }

        public static IDictionary ReturnIDictionary()
        {
            return ReturnDictionary();
        }

        public static IDictionary ReturnNestedIDictionary()
        {
            return ReturnNestedDictionary();
        }
public static IDictionary AcceptNestedDictionary(Dictionary<string, object> dictionary)
        {
            return dictionary;
        }
public static IDictionary AcceptIDictionary(IDictionary dictionary)
        {
            return dictionary;
        }

The following table shows the different combinations of Dictionary output (rows) being passed into node accepting Dictionary inputs (columns):

	Dictionary<string, object>	IDictionary
Dictionary<string, object>	Y	Y
IDictionary	Y	Y
Nested Dictionary	Y	Y
Nested IDictionary	Y	Y
Dictionary w/ user-defined type	Y	Y
IDictionary w/ user-defined type	Y	Y
Arbitrary Dynamo Dictionary	Y	Y
Dictionary w/ List	Y	Y
Idictionary w/ List	Y	Y

Declarations

Check these if you believe they are true

• The code base is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning, and are documented in the API Changes document.

Reviewers

@saintentropy

FYIs

@jnealb

[aparajit-pratap]

I don't see any necessity for the type conversion in this case. This conversion was throwing the error for the input object (DesignScript.Builtin.Dictionary) not being an IConvertible in the first place.

[aparajit-pratap]

Thanks @erfajo. Yes, that's one way to do it but we are also trying to fix the generic dictionary case.

[alfarok]

@aparajit-pratap Changes look good to me. Just to confirm the previous behavior still functioned as expected but the node accepting the generic dictionary as an input displayed in a warning state?

Scratch that last question, I see what was going on

Let me know when this is ready for a final look, you mentioned you were adding some additional testing

[aparajit-pratap]

Thanks @alfarok for the review and testing; I've added some more tests. Merging.