Currently modules are initialized as QQuickItems. In order to be able to
add custom properties for modules to set in the future, introduce
InitialStartModule as the top-level QML object for modules to
initialize.
Currently only two properties are implemented: `available` for whether
to show the module in the wizard, and `contentItem` for the visual
module item.
This is partially an emergency fix also for
https://invent.kde.org/plasma/plasma-mobile/-/issues/404, which was
potentially introduced by https://invent.kde.org/plasma/plasma-mobile/-/merge_requests/582
This MR extracts the screen brightness implementation from initialstart
to a QML plugin, and also ports the action drawer brightness slider
implementation to it. This avoids importing the powerdevil screen
brightness plugin on the lockscreen, which apparently has a race
condition that causes it to sometimes segfault.
Adds an experience for users on first login, allowing some basic configuration.
This is separate from a first start wizard, which would run as a separate user with elevated permissions, and include options that an installer would have.
