[Windows] Fyne chooses app language based on system *region* and not language setting

[dweymouth]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

On Windows, Fyne apps choose the language that corresponds to the region configured in the Windows i18n settings instead of the language. See dweymouth/supersonic#509 for details.

How to reproduce

Run a fyne app with translations with the Windows region set to one language and the system language set to another

Screenshots

No response

Example code

n/a

Fyne version

develop

Go compiler version

n/a

Operating system and version

Windows

Additional Information

No response

[sdassow]

This reminds me of jeandeaual/go-locale#27, and it seems Windows has a similar API call: GetUserPreferredUILanguages.