Overlay the shell's status panel and quicksettings panel over the lockscreen, instead of rendering a second copy in the lockscreen theme. This will allow us to improve the lockscreen loading speed.
Key changes:
- Overlay quicksettings window and the status bar over the lockscreen when it is shown
- Refactor the top panel's showing logic to be cleaner (as it supports various overlay modes over fullscreen apps already)
- Implement lockscreen support to the status bar and quicksettings panel in the to panel
- Forward quicksettings panel requests for "unlock" over DBus to the lockscreen
- Add "raiselockscreen" QML plugin to easily request a window to be raised over the lockscreen
Notes:
- Now that we are sharing the quicksettings panel from the shell, notifications that are already there will be shown on the lockscreen (compared to right now, where only new notifications would be shown)
Depends on:
- https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/2339
- https://invent.kde.org/plasma/kscreenlocker/-/merge_requests/283
- https://invent.kde.org/plasma/kwin/-/merge_requests/7839
Implements: https://invent.kde.org/plasma/plasma-mobile/-/issues/199

This merge request implements a more mobile optimized solution for popup notification.
-
The current controls are:
- Swipe up to move the notification to the notification center.
- Swipe left/right to dismiss the notification entirely.
- If multiple popup notifications are grouped together, tap on the bottom area to view them in a expanded view.
What still needs to be done:
- ~~For notification without a default action, tapping on them should probably open up the associated app.~~ Note: I think I will add this in a separate merge request as it probably should be the case regardless if the notification is a popup
- ~~Swiping down on a notification currently does nothing. Maybe we should map this to a notification action?~~ Note: I have some ideas I will try later, though for now, I will leave this action blank
- ~~The expanded view of notifications should be able to be dismissed by swiping up/down on the top/bottom of the list.~~ Note: Added
- Investigate further into how to remove the current desktop popup notifications.
- ~~Code clean up.~~ Note: The code is at least a bit better
Single popup notification:

Multiple popup notifications:

Multiple popup notifications in the expanded view:

Any feedback would be greatly appreciated.
This avoids having to completely load the quicksettings, status bar,
media widget, and notifications list from scratch when the view changes.
We now have a single instance of each component which is reparented to
the new view (portrait/landscape).
Fixes https://invent.kde.org/plasma/plasma-mobile/-/issues/406
BUG: 484054
This is a potential fix for the input to stop working. There was unused code for passwordless login that could cause the "waitingForAuth" variable to never be set to false after user input.