refactor: replace RegexUtils.MatchNamespaces with inline StartsWith

The RegexUtils.MatchNamespaces helper simply delegates to
string.StartsWith. Inline the check directly in ArchBuilder to
remove an unnecessary indirection. The remaining RegexUtils methods
(MatchGetPropertyName, MatchSetPropertyName) are still in use.

Signed-off-by: Alexander Linne <alexander.linne@tngtech.com>

Author: alexanderlinne

ArchUnitNET/Loader/ArchBuilder.cs

@@ -90,7 +90,10 @@ public void LoadTypesForModule(ModuleDefinition module, string namespaceFilter)
             var currentTypes = new List<IType>(types.Count);
             types
                 .Where(typeDefinition =>
-                    RegexUtils.MatchNamespaces(namespaceFilter, typeDefinition.Namespace)
+                    (
+                        namespaceFilter == null
+                        || typeDefinition.Namespace.StartsWith(namespaceFilter)
+                    )
                     && typeDefinition.CustomAttributes.All(att =>
                         att.AttributeType.FullName
                         != "Microsoft.VisualStudio.TestPlatform.TestSDKAutoGeneratedCode"