Make SelectionHandleType internal (#20908)

* made selection handle type internal

* update apidiff

api/Avalonia.nupkg.xml

@@ -409,6 +409,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Controls.Primitives.SelectionHandleType</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Controls.Remote.RemoteServer</Target>
@@ -883,6 +889,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Controls.Primitives.SelectionHandleType</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Controls.Remote.RemoteServer</Target>

src/Avalonia.Controls/Primitives/SelectionHandleType.cs

@@ -3,7 +3,7 @@
     /// <summary>
     /// Represents which part of the selection the TextSelectionHandle controls.
     /// </summary>
-    public enum SelectionHandleType
+    internal enum SelectionHandleType
     {
         /// <summary>
         /// The Handle controls the caret position.