Update groupnode features to be compatible with frontend v1.2.64

[christian-byrne]

In Comfy-Org/ComfyUI_frontend#950, the prefix for group nodes was changed from workflow/ to workflow>, which caused an issue with saving workflows when the manager was installed.

I have tested these changes on workflows containing group nodes saved from the following states:

• Frontend-1.2.42-WITH_Manager.json

  (before any changes to group nodes)

• Frontend-1.2.42-WITHOUT_Manager.json

  (before any changes to group nodes)

• Frontend-1.2.63-WITH_Manager.json

  (After Fix group node bookmarking Comfy-Org/ComfyUI_frontend#950)

• Frontend-1.2.63-WITHOUT_Manager.json

  (After Fix group node bookmarking Comfy-Org/ComfyUI_frontend#950)

• Frontend-1.2.64-WITH_Manager.json

  (After Fix group node naming compatibility Comfy-Org/ComfyUI_frontend#969)

• Frontend-1.2.64-WITHOUT_Manager.json

  (After Fix group node naming compatibility Comfy-Org/ComfyUI_frontend#969)

• Legacy-Frontend-WITH_Manager.json

Any group nodes saved to workflows in the past 2 days while using the manager and the latest frontend will not be loadable since the groupNodes section of the workflow will have been never properly set. Example: test.json