Use Concrete `Shape` types in constructors?

[LPGhatguy]

Currently, all of the shapes are constructed with an API that looks like this:

JPC_API bool JPC_FooShapeSettings_Create(const JPC_FooShapeSettings* self, JPC_Shape** outShape, JPC_String** outError);

but I wonder if we should treat this, conceptually, as binding to the constructors of the shape types themselves:

JPC_API bool JPC_FooShape_new(const JPC_FooShapeSettings* settings, JPC_FooShape** outShape, JPC_String** outError);