The context menu for the Transfer Deadletter subqueue is in a bad state

[ErikMogensen]

It looks like this:

Also, when a menu item is selected it will execute the actions associated with the two top menu items.

I suggest the same context menu should be used for the Transfer DLQ as the standard DLQ. Also, as much code as possible should be shared between them. This also applies to the code handling queues and subscriptions, where duplicate code should be minimized.

[ErikMogensen]

Fixed in #768