Enhance the update-dependencies script:

- Add the new version number to the commit and PR message.
- Check if anything has been updated and no-op if there wasn't anything updated.
- Add support to CC indviduals on the PR.

scripts/update-dependencies/BuildContextProperties.cs

@@ -0,0 +1,30 @@
+// 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.Collections.Generic;
+using Microsoft.DotNet.Cli.Build.Framework;
+
+namespace Microsoft.DotNet.Scripts
+{
+    public static class BuildContextProperties
+    {
+        public static List<DependencyInfo> GetDependencyInfos(this BuildTargetContext c)
+        {
+            const string propertyName = "DependencyInfos";
+
+            List<DependencyInfo> dependencyInfos;
+            object dependencyInfosObj;
+            if (c.BuildContext.Properties.TryGetValue(propertyName, out dependencyInfosObj))
+            {
+                dependencyInfos = (List<DependencyInfo>)dependencyInfosObj;
+            }
+            else
+            {
+                dependencyInfos = new List<DependencyInfo>();
+                c.BuildContext[propertyName] = dependencyInfos;
+            }
+
+            return dependencyInfos;
+        }
+    }
+}