Address invalid localization files

[jonasraoni]

Describe the bug
Some of our localization files might have an invalid syntax, they might work, due to lax parsers, but also cause unexpected issues with other softwares:

• Weblate might wipe out unrelated content: pkp/ops@cc6187b
• The gettext package might ignore the text: Handling of defective .po files php-gettext/Gettext#282

Solution

• Ensure the .po files are valid at build time.
• For stable-3_3_0 the lax behavior should be kept at runtime to avoid breaking plugins.
• Fix the localization files

What application are you using?
OJS/main

[jonasraoni]

@asmecher I've created a PR for the pkp-lib/main here:

• Bugfix/main/8081 fix invalid locales #8094

I've added a generic validator for the locale files, and most of the fixes are to satisfy the requirements and warnings of the msgfmt validator.

I've tried to isolate the commits, except the 4f379aa... There I used the gettext package to setup the plurals, and it also formatted and removed duplicated entries (inside the same file).

If everything sounds fine, I'll update the other branches.

p.s.: I'm able to reduce the line-break noise by doing a small change to the gettext package.

[jonasraoni]

For the stable-3_3_0, I can pass my modified validator through the locale files, and fix the breaking issues.

I also think it's ok to add the validate-locale.sh in a non-breaking way (e.g. emit errors without failing the build)

[asmecher]

Please hold off on this until we've reached a decision about translation workflows on this discussion: #8038

[jonasraoni]

Ok! So I'll just commit fixes for the broken keys (e.g. missing quotes, bad escaping, ...).

[asmecher]

Yes please -- I've recently merged translations from Weblate so now is a good time.

[jonasraoni]

Just to confirm, I've updated the broken files.

[jonasraoni]

@asmecher I've reviewed and moved the fixes related to duplicated keys here #8119

Also, I fixed the syntax errors on stable-3_3_0.