[Fix]: Data values not formatted when coming from fields plugin custom fields

[jdurand-teclib]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes !45898
• Here is a brief description of what this PR does:
  • Fix an issue where data coming from fields plugin's custom fields are not passed through the formatting process before being injected in database.

No unit test were written because they would have involve references to Fields plugin, thus failing in the GitHub environment, as it is not linked to Fields plugin.

[Rom1-B]

!45898 also reports comma-decimal numbers from Fields custom fields failing to import, not just dates. GLPI's numeric datatype is 'decimal'/'number', never 'float', so this fallback won't trigger reformatFloat() for them. Follow-up planned?