[Feature]: Implement ReferenceSubsettingExtensions

[samatstariongroup]

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of the SysML2.NET
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Description

The ReferenceSubsettingExtensions class in SysML2.NET/Extend/ReferenceSubsettingExtensions.cs contains 1 extension method(s) that compute derived properties for the IReferenceSubsetting interface. These methods currently throw NotSupportedException and need to be implemented.

Checklist

• IFeature ComputeReferencingFeature(this IReferenceSubsetting)

System Configuration

• SysML2.NET version: 0.19.0
• Source file: SysML2.NET/Extend/ReferenceSubsettingExtensions.cs