How do you move an app from one library catalog to another?

you can't..

you can provide feedback to Apple about how you'd like the App Library to be improved..

Feedback - iPhone - Apple

Within App Library, the ability to move apps from App Library folder to another is not supported. You can certainly as we've always had the ability to do, create our own folders on our primary home screens and put apps in those folders and name the folders as we so choose.