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/src/features/admin-center/admin-center.slice.ts

@@ -105,7 +105,6 @@ export const updateHolidaySettings = createAsyncThunk(
   async (settings: IOrganizationHolidaySettings) => {
     const { holidayApiService } = await import('@/api/holiday/holiday.api.service');
     await holidayApiService.updateOrganizationHolidaySettings(settings);
-    await adminCenterApiService.updateOrganizationHolidaySettings(settings);
     return settings;
   }
 );
@@ -164,6 +163,10 @@ const adminCenterSlice = createSlice({
         ? (state.isUpgradeModalOpen = false)
         : (state.isUpgradeModalOpen = true);
     },
+    clearHolidaysCache: state => {
+      state.holidays = [];
+      state.holidaysDateRange = null;
+    },
   },
   extraReducers: builder => {
     builder.addCase(fetchBillingInfo.pending, (state, action) => {
@@ -264,7 +267,7 @@ const adminCenterSlice = createSlice({
   },
 });
 
-export const { toggleRedeemCodeDrawer, toggleUpgradeModal } = adminCenterSlice.actions;
+export const { toggleRedeemCodeDrawer, toggleUpgradeModal, clearHolidaysCache } = adminCenterSlice.actions;
 
 // Selectors for optimized access
 export const selectHolidaysByDateRange = createSelector(