Ensure that all of the variables have their initial state fetched at the
start with the shell DBus client. Also ensure that they only emit
property changes when they actually happen.
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

Disables gesture navigation when Action Drawer, Notification Popup Drawer, or VolumeOSD are visible as activating the task switcher in these situation can feel a bit weird.
Note:
~~Draft for in till I can get side loading working again so I can test it on device.~~
Still can't seem to get side loading working quite yet. Though, I did run the test I could from my laptop and it does seems to be working fine, so I will be removing this from draft.
These changes make the navigation and status bar accessible from within fullscreen applications by allowing the user to tap on the top or tap or drag on the bottom of the screen.
Also, since the top panel is now over top of all fullscreen applications, this moves the action drawer swipe area back into the status bar.
