Diagram Model References show up as archimate-diagram-model

### Version of jArchi, Operating System

Archi Version: 4.8.1 (tested on 4.7.# as well)
jArchi Version: 1.10.202101121529
MacOS: 10.15

### Expected Behavior
I'm making an assumption as to how this behave since the documentation around this area is a bit fuzzy but....

If a view contains References to other views/diagrams (i.e. dragging a view/diagram from the navigation tree onto a view) it should show up as type: diagram-model-reference.

### Actual Behavior
Diagram Reference Objects show up as type: archimate-diagram-model.

### Steps to Reproduce the Behaviour (with attached test files/script)
1. Create several views/diagrams in a model
2. Drag said views/diagrams from the navigation tree onto a view
3. Execute a script that displays the view/diagram children and type

[archimate-diagram-model-defect.archimate.zip](https://github.com/archimatetool/archi-scripting-plugin/files/6971607/archimate-diagram-model-defect.archimate.zip)

[diagram_ref_bug.ajs.zip](https://github.com/archimatetool/archi-scripting-plugin/files/6971613/diagram_ref_bug.ajs.zip)

Start by opening the attached archimate-diagram-model-defect.archimate file in Archi and running diagram_ref_bug.ajs. Compare the reported types for diagram references with the expected diagram-model-reference value. Done means the reproduced references are reported with the correct type without regressing the other child types.

Written by the indexing model from the issue text.