Added new subsystems

Author: KathleenDollard

src/System.CommandLine.Subsystems/InvocationSubsystem.cs

@@ -0,0 +1,11 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.CommandLine.Subsystems;
+using System.CommandLine.Subsystems.Annotations;
+
+namespace System.CommandLine;
+
+public class InvocationSubsystem(IAnnotationProvider? annotationProvider = null)
+    : CliSubsystem(InvocationAnnotations.Prefix, SubsystemKind.Invocation, annotationProvider)
+{}

src/System.CommandLine.Subsystems/Subsystems/Annotations/InvocationAnnotations.cs

@@ -0,0 +1,13 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace System.CommandLine.Subsystems.Annotations;
+
+/// <summary>
+/// IDs for well-known Version annotations.
+/// </summary>
+public static class InvocationAnnotations
+{
+    internal static string Prefix { get; } = nameof(SubsystemKind.Invocation);
+
+}

src/System.CommandLine.Subsystems/Subsystems/Annotations/ValidationAnnotations.cs

@@ -0,0 +1,13 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace System.CommandLine.Subsystems.Annotations;
+
+/// <summary>
+/// IDs for well-known Version annotations.
+/// </summary>
+public static class ValidationAnnotations
+{
+    internal static string Prefix { get; } = nameof(SubsystemKind.Validation);
+
+}

src/System.CommandLine.Subsystems/Subsystems/SubsystemKind.cs

@@ -6,12 +6,14 @@ namespace System.CommandLine.Subsystems;
 public enum SubsystemKind
 {
     Other = 0,
+    Diagram,
+    Completion,
     Help,
     Version,
-    Value,
+    Validation,
+    Invocation,
     ErrorReporting,
-    Completion,
-    Diagram,
-    Response
+    Value,
+    Response,
 }
 

src/System.CommandLine.Subsystems/ValidationSubsystem.cs

@@ -0,0 +1,11 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.CommandLine.Subsystems;
+using System.CommandLine.Subsystems.Annotations;
+
+namespace System.CommandLine;
+
+public class ValidationSubsystem(IAnnotationProvider? annotationProvider = null)
+    : CliSubsystem(ValidationAnnotations.Prefix, SubsystemKind.Validation, annotationProvider)
+{ }