Misc fixes to sound module related to autodetect

[ctrlaltca]

1. Sound options: don't immediately save changes when sound system gets autodetected.
   Instead of changing the value of KVI_OPTION_STRING(KviOption_stringSoundSystem) inside KviSoundPlayer::detectSoundSystem, return the detected value and let the caller handle it
   fix Settings are changed even when clicking Cancel #2667

2. If the config-saved sound system is not available anymore, force an autodetect
   fix Automatically autodetect sound system if old one doesn't exist #2668

3. Fixed the "qt" sound system not working under qt6: the QSoundEffect object was method-local and deleted before the sound actually played.

4. Prefer the "phonon" sound system if available over the "qt" sound system, since the latter can only play wav files. changed in point 6

5. Nuke support for Arts (KDE2/3 sound server) and ESD (Gnome sound server before 2009)

6. Replace QSoundEffect with QMediaPlayer to support more file formats. Adjust the priority of "qt" sound system in autodetect

[DarthGandalf]

https://doc.qt.io/qt-6/videooverview.html#supported-media-formats says it's not only wav supported

[ctrlaltca]

That doc is valid for QMediaPlayer. The doc for QSoundEffect is: https://doc.qt.io/qt-6/audiooverview.html#low-latency-sound-effects
It it doesn't add further dependencies, we could switch to QMediaPlayer anyway

[DarthGandalf]

It it doesn't add further dependencies, we could switch to QMediaPlayer anyway

Yeah, that would be closer to phonon experience

I'll try this locally before approving

[ctrlaltca]

@DarthGandalf : switched to QMediaPlayer, if you want to give it a try