[5.37] Geometry Picker Change Event - Indicate Operation - Add/Remove

VertiGIS Studio Workflow 5.37 sets the change event's argument property to "add" or "remove" for the Geometry Picker.

The Geometry Picker Change Event doesn't give an indication of what triggered the change. It should as minimum include whether it was an Add or a Remove as part of the FormEventData.

Better yet include the actual value of the item that was added/removed as its own property of the form FormEventData.