Weblate uses the wrong format when creating new XWiki files

[surli]

Describe the issue

Same issue as #2980 but for XWiki formats in Weblate. Basically XWiki formats follow Java formats so they should use filename with a underscore for the language locale, and not a dash.
The fix is most probably same as a30a15a but for XWiki formats.

I already tried

• I've read and searched the documentation.
• I've searched for similar filed issues in this repository.

Steps to reproduce the behavior

1. Create a component with type "XWiki Properties" (it does not matter which encoding)
2. Add a new language "English (United Kingdom)"
3. Check the created file name - it is {filename}_en-GB.properties

Expected behavior

The file should be created as {filename}_en_GB.properties

Screenshots

No response

Exception traceback

No response

How do you run Weblate?

PyPI module

Weblate versions

No response

Weblate deploy checks

No response

Additional context

No response

[github-actions]

Thank you for your report; the issue you have reported has just been fixed.

• In case you see a problem with the fix, please comment on this issue.
• In case you see a similar problem, please open a separate issue.
• If you are happy with the outcome, don’t hesitate to support Weblate by making a donation.

[github-actions]

Thank you for your report; the issue you have reported has just been fixed.

• In case you see a problem with the fix, please comment on this issue.
• In case you see a similar problem, please open a separate issue.
• If you are happy with the outcome, don’t hesitate to support Weblate by making a donation.