Implemetation NamespaceExtensions

[antoineatstariongroup]

Prerequisites

• I have written a descriptive pull-request title
• I have verified that there are no overlapping pull-requests open
• I have verified that I am following the SysML2.NET code style guidelines
• I have provided test coverage for my change (where applicable)

Description

• Update to latest uml4net to fix operation implementation
• implementation of the Namespace derived properties and Operation

[samatstariongroup]

The SysML v2 rule for importedMemberships excludes members that clash with any
owned member's name or shortName. This implementation only hashes
MemberName. Two imported members with the same MemberShortName (or an owned
member sharing a MemberShortName with an imported member) will slip through.
Either:

• Extend the hash sets to also consider MemberShortName, or

[samatstariongroup]

ImportedMemberships([]) is re-evaluated for every ownedImport until a match
is found — O(imports × import cost) per call, and VisibilityOfOperation itself
is called inside ComputeVisibleMembershipsOperation's .Where filter, so the
outer loop multiplies it again. Materialise once:

var import = namespaceSubject.ownedImport.FirstOrDefault(x =>
((ICollection)x.ImportedMemberships([])).Contains(mem));

…and ideally cache across the enclosing ComputeVisibleMembershipsOperation
call by using namespaceSubject.ImportedMemberships([]) once and reusing it.

[samatstariongroup]

CLAUDE.md calls out "prefer indexer syntax over LINQ methods when
applicable". After the count check, OwnedRelatedElement[0] is correct and
faster (avoids the second enumeration that Single() performs).

[samatstariongroup]

namespaceSubject.importedMembership is itself the derived property that our
own ComputeImportedMembership produces. Calling
ownedMembership.Union(importedMembership) plus ComputeImportedMembership(…)
elsewhere ends up recomputing the import chain at least twice per
ComputeMembership call. Consider referencing a single source of truth — e.g.
namespaceSubject.ImportedMemberships([]) — or adding a short // Why: comment
if the duplication is intentional for layering reasons.