Automatic screen brightness based on ambient light

A common feature that other DEs or OSs already have for a long time is automatic screen brightness. This feature is particularly useful for laptop/mobile users so they don't have to frequently adjust the brightness when the ambient light changes.

The plan is to add automatic screen brightness in PowerDevil's backend, and provide an option in the battery monitor widget and the system settings KCM.

Some examples to follow:

• https://gitlab.gnome.org/GNOME/gnome-settings-daemon/-/commit/afd1ec179f8f497a8068fc413102c2ba1b42a26f

• https://gitlab.gnome.org/GNOME/gnome-settings-daemon/-/commit/bbdef3f87c6a16588cc05dfd798e610b327ebfbd

• Add support for ambient light devices supported by iio-sensor-proxy

  • Optional depend on iio-sensor-proxy, and watch net.hadess.SensorProxy dbus interface
  • Adjust brightness on receiving LightLevel property changed signals
  • Make transitions less rigid

• Add an option in the battery monitor widget

• Add an option in the KCM (can be done after the KCM is ported to QML)

"Same river" series

• Automatic screen brightness reacts on sensor jitter
• Max brightness level stuck at dim setting intensity after inactivity before suspend
• (Pinephone)Screen auto brightness control and low ambient luminosity
• Automatic brightness too abrupt
• Improve heuristics for automatic brightness control
• Automatic brightness changes it too often
• Make the automatic display brightness control function more visible