Fix: search crash on duplicate field names

[Rom1-B]

Checklist before requesting a review

Please delete options that are not relevant.

• 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 !45192
• Two containers can legitimately define a dropdown field with the same name, so both share the same underlying dropdown table.
• Searching on the related itemtype then crashed with a Twig runtime error, because the plugin looked up the field by name instead of by its unique id, and the lookup found two matching rows instead of one.

An exception thrown during rendering template ("`PluginFieldsField::getFromDBByCrit()` expects get one result, 2 found in query "SELECT `id` FROM `glpi_plugin_fields_fields` WHERE `name` = 'accessoirefield' AND `multiple` = '1'".") in "pages/generic_list.html.twig" line 37.

• The field is now identified by its id, which is already computed when the search options are built and used elsewhere in the plugin for the same purpose.

Screenshots (if appropriate):

[stonebuzz]

LGTM