Ungrouping legacy include nodes with nested operators generates corrupted workflow

[glopesdev]

Following #1126 it seems like ungrouping legacy include nodes with nested operators results in a corrupted workflow after the upgrade.

This seems to be caused by the editor not converting the existing workflow to/from inspectable graph before and after the workflow upgrade. The current upgrade routine requires workflows not to be decorated with any inspectors.

There are two options for fixing the issue:

1. Convert from/to inspectable graph always before upgrading.
2. Generalize the upgrade routine to work for any decorator. Generalization of routines for decorator type nodes is waiting for the next major release so we might have to go for a temporary workaround similar to the one used for DisableBuilder nodes in Ensure upgrading does not re-enable disabled nodes #1132.