hdrcalibrator: remove fullscreen average calibration page again
Unfortunately on most common HDR displays, it doesn't work as expected, and just results in the peak luminance. This confused a lot of users, which was the opposite of its intended purpose.
If available, the max average luminance reported in the EDID is instead used to recommend a sensible max reference luminance value to the user.
(cherry picked from commit 07bdaca5)
Co-authored-by: Xaver Hugl xaver.hugl@kde.org