Refactor ReadProfileHandler and add Buttons property

Updated `ReadProfileHandler` to assign buttons directly to the `profile` object before mapping to `ProfileDto`. This ensures the `Buttons` property is populated correctly. Added a new `[NotMapped]` property `Buttons` of type `IEnumerable<Button>?` to the `Profile` class to hold associated buttons.

src/WorkFlow.Domain/Entities/Profile.cs

@@ -27,4 +27,7 @@ public class Profile
 
     [NotMapped]
     public IEnumerable<ProfileObject>? Objects { get; set; }
+
+    [NotMapped]
+    public IEnumerable<Button>? Buttons { get; set; }
 }