Graph Editor: Does not create the correct version of versioned nodes

[kwokcb]

Issue

There is insufficient information set on the node instance when creating different versions of versioned nodes If you create both versions of std surface then you end up with the default version being created for both which is incorrect. i.e. you get this:

<?xml version="1.0"?>
<materialx version="1.38">
  <standard_surface name="standard_surface_surfaceshader" type="surfaceshader" xpos="12.391304" ypos="-2.172414" />
  <standard_surface name="standard_surface_surfaceshader_100" type="surfaceshader" xpos="13.789855" ypos="-4.525862" />
</materialx>

As no version is specified both have the same version even though from the UI different node versions we're asked for.

The same thing happens with UsdUVTexture which is versioned:

<?xml version="1.0"?>
<materialx version="1.38">
  <UsdUVTexture name="UsdUVTexture" type="multioutput" xpos="14.985507" ypos="-5.362069" />
  <UsdUVTexture name="UsdUVTexture_23" type="multioutput" xpos="12.608696" ypos="-4.948276" />
</materialx>