[configuration] Translate configuration module (db translations only)

[HachemJ]

Brief summary of changes

This PR translates the configuration module in French. It only includes db translations.

This PR also refactors configuration localization to use ConfigI18n, following the existing implementation in authentication.class.inc.

It removes the unnecessary projectDescription helper from php/libraries/Settings.class.inc and its use in projectDescription.class.inc.

Finally it renames the duplicate 'HTTP Request Log Level' mislabel in RB_ConfigSettings.sql to 'PHP Exception Log Level' for the exception_log_level configuration setting.

Note: I used AI for translations but double-checked them as a fluent French speaker.

Testing instructions (if applicable)

For anyone that will test this PR : I'm not sure what it is, but sometimes I have to reload the page multiple times for all db translations to appear. It might be something specific to this module or something happening with my machine, but this is why I refresh the page twice in the 'After' video.

1. run make testdata to include the new raisinbread changes
2. delete project/locale
3. copy raisinbread/locale into project/locale
4. run make dev (make sure it ran the msgfmt --use-fuzzy -o table.mo table.po commands)
5. Go to 'Admin' -> 'Configuration'
6. Switch the language to 'French'
7. Verify that the left menu items, section headings, section descriptions, field labels and field descriptions are translated
8. Also explore the other three pages by clicking the three “click here” links at the top of the page

Before:

Screen.Recording.2026-07-12.at.6.54.10.PM.mov

After:

Screen.Recording.2026-07-12.at.7.04.08.PM.mov

Link(s) to related issue(s)

• Resolves [configuration] Module not translated #10647 (Reference the issue this fixes, if any.)