(OPC UA) Enumeration handling in OPC UA variable instances is faulty

Requirement Concerned:

As a User, I want complete and accurate representation of enumeration properties in OPC UA variable instances, to get a compliant information model.

Description:

Bug 1: Currently, when an enumeration is utilized as a DataType (e.g., BACnetBinaryPV), the child property EnumStrings is missing (see screenshot-1.png). This issue also extends to Enumerations with a child property EnumValues. The expected behavior is for each enumeration instance to include its corresponding child property. To optimize memory usage, a simple reference HasProperty should be established from the variable instance (with the datatype "enumeration") to the Enumeration definition’s child property (see screenshot-2.png).

Bug 2: There's an issue where if a reference is manually added to circumvent the current bug, clicking the "Apply" button causes the editor tab to close unexpectedly (see screenshot-3.png).

Steps to Reproduce Bug 1:

1. Create a variable instance with an enumeration as its DataType, such as BACnetBinaryPV.
2. Observe the absence of EnumStrings or EnumValues as a child property in the instance.

Steps to Reproduce Bug 2:

1. Manually add a reference to the enumeration instance to the child property from the enumeration definition.
2. Click the "Apply" button and note the unexpected closing of the editor tab.

CSS project is included. However, this should apply to every enumeration/information model.