IUserDialogs is now registered with service collection

Refactored the MauiAppBuilder extension to be shared by all platforms, add servicecollection registation for instance

Controls.UserDialogs.Maui/Shared/MauiAppBuilderExtension.cs

@@ -0,0 +1,15 @@
+namespace Controls.UserDialogs.Maui;
+
+public static class MauiAppBuilderExtension
+{
+    public static MauiAppBuilder UseUserDialogs(this MauiAppBuilder builder, Action configure = null)
+    {
+        UserDialogs.Instance = new UserDialogsImplementation();
+
+        configure?.Invoke();
+
+        builder.Services.AddTransient((s) => UserDialogs.Instance);
+
+        return builder;
+    }
+}

Controls.UserDialogs.Maui/Shared/UserDialogs.cs

@@ -1,6 +1,6 @@
 namespace Controls.UserDialogs.Maui;
 
-public partial class UserDialogs
+public class UserDialogs
 {
     static IUserDialogs _currentInstance;
     public static IUserDialogs Instance
@@ -14,6 +14,4 @@ public static IUserDialogs Instance
         }
         set => _currentInstance = value;
     }
-
-    public static partial MauiAppBuilder UseUserDialogs(this MauiAppBuilder builder, Action configure = null);
 }