Make the plugin compatible with GLPI 11 and 12 - #72

Related to #59

GLPI 11 and 12 compatibility

This PR only makes the plugin run on both GLPI 11 and GLPI 12 (bumped to 1.4.1). It contains no translation files; those are in a separate PR (pt_BR translation).

Changes

• setup.php: version 1.4.1, minimum GLPI 11.0.0, maximum 12.0.99.
• advancedforms.xml: add a 1.4.1 entry with compatibility >=11.0.0; the 1.4.0 entry is unchanged.
• TicketReservationRequest: remove the redeclared static properties ($itemtype, $items_id, $rightname) and set the inherited ones during plugin init. These are untyped in GLPI 11 and typed in GLPI 12, so redeclaring them with either form is a fatal error on the other version.
• Tree cascade dropdown (question type, children controller, text condition handler): handle both getDefaultValueItemId()/items_id (GLPI 11) and getDefaultValuesItemIds()/items_ids (GLPI 12).
• config_form.html.twig: render the _glpi_csrf_token field only on GLPI 11; GLPI 12 no longer uses CSRF tokens.
• Reservation calendar (reservation_question.html.twig, ReservationQuestionWidget.js): on GLPI 11 use the core FullCalendar v5 with its stylesheet; on GLPI 12 load the bundled FullCalendar v6.

Validation

• PHP and JavaScript syntax checks pass.
• Static check of the APIs against GLPI 11.0.11 and 12.0.0 sources.
• PHPUnit was not run, and 11.0.0 as the minimum has not been tested.