Converting a node that is not attached to anything (input and output) to a subgraph via the right click menu option "Convert to Sub Graph" will create a corrupt subgraph

Repro Steps:
1. Use a project containing Universal Render Pipeline
2. Right click in assets -> Create -> Shader -> PBR Graph
3. Open the PBR Graph asset
4. Create a new Node (Any node appears to work but I used Blend)
5. Ensure the new node is not connected to anything
6. Right click on the node -> Convert to Sub-graph
- A Warning will appear in the Editor at this point: Warning in Graph at Assets/DoesThisBreak.shadersubgraph at node Output: A Sub Graph must have at least one output slot
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)
- Subgraph from the Shadergraph View will have an error as well *Image attached
- This is enough to reproduce the issue, further steps will create worse behavior for the user

7. Go into the sub-graph
8. Hook up the node to the output.
9. Return to the Shadergraph and left click on the Sub Graph
- Notice the node will be "stuck" to your mouse cursor
10. Hit the Delete button to attempt to delete the Sub Graph
- Notice you are unnable to delete the Sub Graph

Actual Results:
Sub Graph becomes corrupt and causes multiple issues.
- Editor Warning appears
- Editor Errors appear (ArgumentExceptions & NullRefrenceExceptions)
- Sub-Graph will get stuck to the user's mouse cursor if they left click on it while in the Shadergraph view
- Sub-Graph will not be able to be deleted from the shadergraph view
- Deleting the Sub-Graph from the assets menu does not allow you to delete it from the shadergraph

Expected Results:
Creating a sub-graph from the right click menu option would not cause any warnings or errors to appear in the editor and allow the user to work from these unhooked nodes within the new sub-graph without issue.