implemented comprehensive accessibility (A11y) support across the app

lib/view/pages/settings/modules_settings_page.dart

@@ -66,6 +66,7 @@ class ModuleSortBody extends StatelessWidget {
                   mainAxisSize: MainAxisSize.min,
                   children: [
                     IconButton(
+                      tooltip: 'Slot entfernen',
                       icon: const Icon(Icons.remove_circle_outline),
                       onPressed:
                           modulesSettings.fixedBottomBarSlots >
@@ -80,6 +81,7 @@ class ModuleSortBody extends StatelessWidget {
                     ),
                     Text('${modulesSettings.fixedBottomBarSlots}'),
                     IconButton(
+                      tooltip: 'Slot hinzufügen',
                       icon: const Icon(Icons.add_circle_outline),
                       onPressed:
                           modulesSettings.fixedBottomBarSlots <