No feedback when stuck waiting for package manager lock

### What Happened?

I inadvertantly started an "Update All" process while having Synaptic open. The process proceeded to certain point but then stalled with the progressbar at 100%, the spinner working, and the cancel button tooltip reading "Waiting". It was not immediate obvious what was causing the wait. Once Synaptic was closed the process completed quickly.

### Steps to Reproduce

1. Start Synaptic or similar process
2. Launch AppCenter and start an "Update All" process
3. Observe that the process proceeds for a while then stalls with no obvious feedback as to reason.

### Expected Behavior

Clear user feedback should be given when an update process cannot complete until a user action is taken

### OS Version

6.x (Odin)

### Software Version

Compiled from git

### Log Output

_No response_

### Hardware Info

_No response_