(fix) Library: BPM display uses decimal separator of selected locale

[ronso0]

fixes #13051

QString::number(double, format, precision) is locale-independent.

IMO this raises the question how we want to display BPM / beats in general:

• Consistent according to selected locale?
  Need to fix WNumber, too.
  Maybe also dialogs like Track Properties ✔️ uses locale
  And WBeatSpinBox ✔️ uses locale
• "International"? (decimal separator is . everywhere)
  Need to adjust library's BPM delegate (it's editor), since that currently correctly uses the selected locale (, or .)

The second commit fixes #13065

The max BPM limit may be moved to some prefs.h file and made available for BPMDelegate, WTrackProperties etc.

[daschuer]

Since we translate Mixxx in various languages, also the decimal separator should be translated.

I can remember a discussion where the decimal comma has been considered as ugly in the bpm display in the skin.

[daschuer]

I would vote for changing the library to localized decimal separator, and everywhere else. We have already the inconsistency between tooltips and grid element.

The number display in the skin could be still an issue, because the comma uses space below the bottom line of the numbers. For that reason I would vote keeping the decimal dot for all.

[ronso0]

I can remember a discussion where the decimal comma has been considered as ugly in the bpm display in the skin.

Yep. And I bet I was part of the comma group ; )

The widget commmit (WNumber etc.) was a test. I'm not sure, and I think I'll revert it for now (after others have taken a look).
But I think display and editor in the library it should be consistent. I can move the first commit (library) to a new PR or the second (widgets).

[daschuer]

Yep. And I bet I was part of the comma group ; )

That would be definitely "correct". Do you have screenshots at hand, maybe the issue is no longer visible or we may default to native separator and allow overriding it by the skin.

[daschuer]

The library commit can be merged as it is.

[ronso0]

I removed f7ed730 and added a comment.
Ready to roll.

[ronso0]

I think #13068 is a good idea nonetheless to make the editor more permissive.

[daschuer]

LGTM, Thank you.