Make the member tree nodes public again

These types were public through release/10.1; the Avalonia port had
dropped them to internal. Plugins build custom tree integrations on
top of the member tree nodes, so restore their 10.1 visibility.
NaturalStringComparer becomes public too, but keeps its static-class
shape.

Assisted-by: Claude:claude-fable-5:Claude Code

ILSpy/TreeNodes/AssemblyReferenceTreeNode.cs

@@ -41,7 +41,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// using ILAmbience escaping plus a generic assembly icon. Children (the
 	/// per-reference type list and transitive references) are not yet implemented.
 	/// </summary>
-	sealed class AssemblyReferenceTreeNode : ILSpyTreeNode
+	public sealed class AssemblyReferenceTreeNode : ILSpyTreeNode
 	{
 		enum LoadState { Unloaded, Loading, Loaded, Failed }
 

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -42,7 +42,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class AssemblyTreeNode : ILSpyTreeNode
+	public sealed class AssemblyTreeNode : ILSpyTreeNode
 	{
 		readonly LoadedAssembly assembly;
 		string? loadError;

ILSpy/TreeNodes/EventTreeNode.cs

@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class EventTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class EventTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IEvent EventDefinition { get; }
 

ILSpy/TreeNodes/ExtensionTreeNode.cs

@@ -39,7 +39,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// methods/properties; the block's own members (methods + properties) appear as
 	/// children of this node when expanded.
 	/// </summary>
-	internal sealed class ExtensionTreeNode : ILSpyTreeNode
+	public sealed class ExtensionTreeNode : ILSpyTreeNode
 	{
 		public ExtensionTreeNode(
 			ITypeDefinition typeDefinition,

ILSpy/TreeNodes/FieldTreeNode.cs

@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class FieldTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class FieldTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IField FieldDefinition { get; }
 

ILSpy/TreeNodes/MethodTreeNode.cs

@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class MethodTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class MethodTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IMethod MethodDefinition { get; }
 

ILSpy/TreeNodes/NamespaceTreeNode.cs

@@ -29,7 +29,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class NamespaceTreeNode : ILSpyTreeNode
+	public sealed class NamespaceTreeNode : ILSpyTreeNode
 	{
 		readonly string name;
 		readonly string fullName;

ILSpy/TreeNodes/NaturalStringComparer.cs

@@ -24,7 +24,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// .NET natural string comparison.
 	/// </summary>
-	internal static class NaturalStringComparer
+	public static class NaturalStringComparer
 	{
 		public static readonly IComparer<string> Instance =
 			System.StringComparer.Create(CultureInfo.CurrentCulture, CompareOptions.NumericOrdering);

ILSpy/TreeNodes/PropertyTreeNode.cs

@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class PropertyTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class PropertyTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IProperty PropertyDefinition { get; }
 

ILSpy/TreeNodes/TypeTreeNode.cs

@@ -33,7 +33,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class TypeTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class TypeTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		readonly TypeDefinitionHandle handle;
 		readonly MetadataFile module;