QApt Package Installer output window silently consumes all keyboard inputs

[sleet01]

Issue:

It appears that the KDE qapt Package Installer takes and consumes all keyboard input until it is closed; mouse input still works.

I've actually noticed this a few times while playing full screen games and installing updates in the background, but could not track down the root cause because <alt>+<tab> would, of course, be silently consumed.

Most recently I experienced this issue while upgrading Chrome using the .deb package; in the middle of browsing (while running the .deb install in the background) I lost all keyboard input. I noticed that QApt was waiting to be closed following a successful install, remembered that the same thing had happened while playing a game recently, and confirmed that keyboard control was returned once I closed the QApt window.

Note: System TTY switching still works, and allows keyboard input. E.g. <alt>-<F2> to switch to the TTY allows logging in to console.

Expected:

Qapt Package Installer consumes no keyboard input unless it is in focus, and certainly does not prevent other focused programs from receiving keyboard input.

Environment:
* Ubuntu 22.04 (Jammy Jellyfish)

* KDE Plasma 5.24.7
** Frameworks: 5.92.0
** Qt: 5.15.3
** Kernel: 5.15.0-59-generic (64-bit)

* QApt packages for Jammy Jellyfish
** gstreamer-qapt/jammy,now 3.0.5-1ubuntu1 amd64
** libqapt3/jammy,now 3.0.5-1ubuntu1 amd64
** libqapt3-runtime/jammy,now 3.0.5-1ubuntu1 amd64
** qapt-batch/jammy,now 3.0.5-1ubuntu1 amd64
** qapt-deb-installer/jammy,now 3.0.5-1ubuntu1 amd64

Repro:

1. Install Ubuntu 22.04 and latest KDE 5 (Plasma)
2. Download the latest Chrome .deb
3. Install the .deb using Dolphin or your browser's Downloads list
4. Provide credentials as necessary
5. Wait for QApt Package Installer window to appear
6. Attempt to use keyboard input on any other program (Note: do not switch to a full-screen application that requires <alt>+<tab> or other hotkeys to leave, or you will be stuck.)