Combine Utils.vb from both AppDesigner and Editors

The `Utils.vb` files in both the AppDesigner and Editors projects are very similar. There is quite a bit of copy/paste code between them. So, it would make sense to consolidate this into a single file. The idea would be to include the file in one project and then simply link to the file in the other project. These files are currently not public, so there wouldn't be an issue with using the same namespace.