Fix(Search): Fix undefined array key during database inventory task

[stonebuzz]

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

When the task involves configuring databases to be inventoried, this request is made through an autonomous curl call.

Under these conditions, $_SESSION['glpiname'] is not initialized with the name of the user who is connecting, which causes the following error when performing a search using the Search.php class:

[2025-09-02 13:29:03] glpiphplog.WARNING:   *** PHP Warning (2): Undefined array key "glpiname" in D:\wamp\www\glpi\src\Search.php at line 729
  Backtrace :
  ...nventory\inc\computergroupdynamic.class.php:183 Search::constructSQL()
  plugins\databaseinventory\inc\task.class.php:244   PluginDatabaseinventoryComputerGroupDynamic->isDynamicSearchMatchComputer()
  src\Plugin.php:1763                                PluginDatabaseinventoryTask::handleInventoryTask()
  src\Inventory\Request.php:420                      Plugin::doHookFunction()
  src\Inventory\Request.php:130                      Glpi\Inventory\Request->handleInventoryTask()
  src\Inventory\Request.php:340                      Glpi\Inventory\Request->handleTask()
  src\Inventory\Request.php:83                       Glpi\Inventory\Request->contact()
  src\Agent\Communication\AbstractRequest.php:359    Glpi\Inventory\Request->handleAction()
  src\Agent\Communication\AbstractRequest.php:271    Glpi\Agent\Communication\AbstractRequest->handleJSONRequest()
  front\inventory.php:100                            Glpi\Agent\Communication\AbstractRequest->handleRequest()
  plugins\glpiinventory\front\communication.php:72   include_once()
  plugins\glpiinventory\index.php:45                 include_once()

This PR forcibly sets $_SESSION['glpiname'] to 'databaseinventory_plugin' (useful for debugging) during the execution of the search, and restores the original value after the call to the Search class.

Fix : #73

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