resolve Python changes to AST module

Created by: zeffii

Addressed problem description

The Set/Get Property MK2 node relies on Python's AST module, which received major upgrades between Python 3.7 (Blender 2.92) and Python 3.9+ ( Blender 2.93). The upgrades to AST module broke the way this nodes parses attributes, because internally certain classes of ast have been depreciated (and have different return behaviours).

Solution description

The solution provides two extra clauses in the if-else logic of the "parse_to_path" function, these clauses show the simplified approach now permitted by the AST module.

Preflight checklist

Put an x letter in each brackets when you're done this item:

• Code changes complete.
• Manual testing done.
• Ready for merge.

resolves https://github.com/nortikin/sverchok/issues/3946

• adds the following aliases nodes and ng
  • nodes: resolves to self.id_data.nodes, use this to work on the current node tree
  • ng: resolves to bpy.data.node_groups