Ensure NoneType when inspecting origin type args contain None

[VegetarianOrc]

What was changed

• Ensure we're using NoneType instead of None when inspecting type args in converter

Why?

When inspecting the origin type args in the converter Dict[None,...] produces the type args (NoneType,...) while dict[None,...] produces the type args (None,...). This change normalizes None to NoneType.

Checklist

1. Closes [Bug] Converter returns bad value converting dict[None, Any] #1237

2. How was this tested:

Existing convert tests were adjusted to capture the expectation that dict[None,...] returns {None:...}.