feat(planning): #62 #63 #64 enhance leave planner with calculation date and entitlement details

- Introduced calculationDate in various service interfaces and snapshots to track the date of planning calculations.
- Added futureEntitlement and includedEntitlement fields to the translation service and respective language files for better user feedback.
- Updated leave-planner.worker to handle calculationDate and declaredDays in requests.
- Enhanced tests to ensure proper handling of calculation dates and artifact retention during planning processes.
- Improved snapshot and explanation outputs to include calculation date for clarity in planning results.

src/app/services/leave-planner.worker.ts

@@ -23,6 +23,8 @@ import {
 } from './leave-planner.core';
 
 type WorkerPlanningRequest = {
+	calculationDate?: string;
+	declaredDays?: unknown;
 	horizon?: { start?: unknown; end?: unknown };
 	balances?: unknown;
 	rules?: unknown;