feat(holiday-settings): implement organization holiday settings management

- Added SQL migration for creating organization holiday settings and state holidays tables with necessary constraints and indexes.
- Implemented API endpoints in AdminCenterController for retrieving and updating organization holiday settings.
- Updated admin-center API router to include routes for holiday settings management.
- Enhanced localization files to support new holiday settings UI elements in multiple languages.
- Improved holiday calendar component to display working days and integrate holiday settings.

worklenz-frontend/public/locales/es/admin-center/settings.json

@@ -13,5 +13,21 @@
   "sunday": "Domingo",
   "saveButton": "Guardar",
   "saved": "Configuración guardada exitosamente",
-  "errorSaving": "Error al guardar la configuración"
+  "errorSaving": "Error al guardar la configuración",
+  "holidaySettings": "Configuración de días festivos",
+  "country": "País",
+  "countryRequired": "Por favor seleccione un país",
+  "selectCountry": "Seleccionar país",
+  "state": "Estado/Provincia",
+  "selectState": "Seleccionar estado/provincia (opcional)",
+  "autoSyncHolidays": "Sincronizar automáticamente los días festivos oficiales",
+  "saveHolidaySettings": "Guardar configuración de días festivos",
+  "holidaySettingsSaved": "Configuración de días festivos guardada exitosamente",
+  "errorSavingHolidaySettings": "Error al guardar la configuración de días festivos",
+  "addCustomHoliday": "Agregar Día Festivo Personalizado",
+  "officialHolidaysFrom": "Días festivos oficiales de",
+  "workingDay": "Día Laboral",
+  "holiday": "Día Festivo",
+  "today": "Hoy",
+  "cannotEditOfficialHoliday": "No se pueden editar los días festivos oficiales"
 }