Default Qt5 scaling works not well for all resolutions

Maybe we can tweak the environment variables using the slider in:
https://github.com/mixxxdj/mixxx/pull/1741

The final solution should work without our custom scaling from Qt4.

Zulip:
https://mixxx.zulipchat.com/#narrow/stream/109695-_support/topic/v2.2E2.2E0.20scaling
https://mixxx.zulipchat.com/#narrow/stream/109171-development/subject/2.2E2.2E0.20release.20progress/near/152504828

It looks like this is a relay annoying one. I will put it to the 2.3 milestone to express this.
Maybe one find time to fix it without using a batch file.

See: https://www.mixxx.org/forums/viewtopic.php?f=3&t=12586

The workaround is described here:
https://mixxx.org/wiki/doku.php/troubleshooting#graphical_user_interface_gui_is_too_big_or_too_small

An other effected user: https://www.mixxx.org/forums/viewtopic.php?f=1&t=12585

That's the reason why I always recommended not to enable this legacy option by default.

one more
https://mixxx.zulipchat.com/#narrow/stream/109695-_support/topic/help

Just to summarize the issue: We can't safely deicde wether scaling makes sense or not on a specific screen. It would for example report 1920px but it might 22" desktop screen or a 10" notebook, so the user needs to be able to adjust the scaling for his context.

can't we use a checkbox in Prefs > Interface to solve this:
[ ] Automatic scaling

Appearantly not all users are technically inclined enough to create a batch file,..

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/9451