Replace keys in Rich Text Editor blocks on clone operations (#19526)

* Regenerate keys in RTE blocks on clone operations

This was already present for BlockList and BlockGrid, but not Blocks in RTE.

* Small adjustment from code review

src/Umbraco.Infrastructure/DependencyInjection/UmbracoBuilder.CoreServices.cs

@@ -352,6 +352,9 @@ public static partial class UmbracoBuilderExtensions
             .AddNotificationHandler<ContentSavingNotification, BlockGridPropertyNotificationHandler>()
             .AddNotificationHandler<ContentCopyingNotification, BlockGridPropertyNotificationHandler>()
             .AddNotificationHandler<ContentScaffoldedNotification, BlockGridPropertyNotificationHandler>()
+            .AddNotificationHandler<ContentSavingNotification, RichTextPropertyNotificationHandler>()
+            .AddNotificationHandler<ContentCopyingNotification, RichTextPropertyNotificationHandler>()
+            .AddNotificationHandler<ContentScaffoldedNotification, RichTextPropertyNotificationHandler>()
             .AddNotificationHandler<ContentCopiedNotification, FileUploadPropertyEditor>()
             .AddNotificationHandler<ContentDeletedNotification, FileUploadPropertyEditor>()
             .AddNotificationHandler<MediaDeletedNotification, FileUploadPropertyEditor>()

src/Umbraco.Infrastructure/PropertyEditors/RichTextPropertyNotificationHandler.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Umbraco.
+// See LICENSE for more details.
+
+using Microsoft.Extensions.Logging;
+using Umbraco.Cms.Core.Models.Blocks;
+
+namespace Umbraco.Cms.Core.PropertyEditors;
+
+/// <summary>
+/// A handler for Rich Text editors used to bind to notifications.
+/// </summary>
+public class RichTextPropertyNotificationHandler : BlockEditorPropertyNotificationHandlerBase<RichTextBlockLayoutItem>
+{
+    public RichTextPropertyNotificationHandler(ILogger<RichTextPropertyNotificationHandler> logger)
+        : base(logger)
+    {
+    }
+
+    protected override string EditorAlias => Constants.PropertyEditors.Aliases.RichText;
+}