Allow changing update queue while some app is being updated

[ceskyDJ]

Describe the feature
Now, when I run updating for some app, it completely blocks all updating buttons, so I can't select more app for updating. I think it will be very good, if I can add other apps to a queue and they will be updated after the first app. There should already be something like updating queue because you can select multiple apps and run updating at once. So, I think it shouldn't been much hard to implement this.

This is a screenshot showing that other buttons (e.g. Obtainium's) are blocked while updating app Collabora Office:

[ceskyDJ]

It has pretty bad UX now. I just have to wait for the previous app to completely update before I can select other app to update. I know there is a batch updating but I'm used to select apps individually from some other app stores and fighting against habits is very hard :(.