Updates navigation event data

Updates the navigation event to include the current date
instead of the week start.

Makes the target date optional when rendering an all-day event.

src/managers/NavigationManager.ts

@@ -288,7 +288,7 @@ export class NavigationManager {
       // Emit period change event for ScrollManager
       this.eventBus.emit(CoreEvents.NAVIGATION_COMPLETED, {
         direction,
-        weekStart: this.currentWeek
+        currentDate: this.currentWeek
       });
       
     });