FIX / Mandatory field validation not enforced on update

[Mary-Clb]

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• 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 !46213
• Mandatory fields on a Tab, Domtab, or "multiple" field were not enforced when updating an existing item, since the check only ran on creation for dom containers. Fixes [GLPI 10.0.9 ] - mandatory fields of Tab block are not mandatory #1268; extends the fix from fix(container.class): Prevent item creation with null value for mandatory fields #1229 to updates and all container types, using the item's already persisted values to avoid false positives.