VSN-2096/ feat: Passenger absence management - Full integration with modern UI/UX

This merge request integrate passenger absence features with some UI/UX improvements.

Changes :

• Integrate passenger absence feature with backend API
• Implement modern UI/UX for absence management screens
• Add French locale support for date pickers
• Visual overview with non-clickable stat cards (En attente, En cours, Validé, Rejeté)
• Disable edit for approved/rejected absences
• Modal dropdown with modern sliders icon for status filtering
• Loading state during initial fetch
• Separate refresh indicator for pull-to-refresh
• Update placeholders and labels