Enhance dashboard service with widget caching and improved query handling

- Introduced a new `widgetCache` structure to manage caching for various dashboard widgets, improving performance and reducing redundant data retrieval.
- Updated the `ClosingSoon` and `Trend` methods in the service to utilize the new caching mechanism, ensuring efficient data access and reducing load on the database.
- Enhanced the `NoticeTypes` and `Countries` methods to implement caching, further optimizing the dashboard's responsiveness.
- Added a new `searchListCache` implementation in the tender service to cache search results, improving the efficiency of tender searches and reducing database load.
- Implemented robust error handling and logging for cache operations, ensuring better visibility into potential issues.

This update significantly enhances the performance and scalability of the dashboard and tender services by integrating effective caching strategies, leading to improved user experience and resource management.

internal/tender/repository.go

@@ -130,6 +130,15 @@ func NewRepository(mongoManager *orm.ConnectionManager, logger logger.Logger) Te
 		*orm.NewIndex("main_classification_idx", bson.D{{Key: "main_classification", Value: 1}}),
 		*orm.NewIndex("publication_date_idx", bson.D{{Key: "publication_date", Value: -1}}),
 		*orm.NewIndex("tender_deadline_idx", bson.D{{Key: "tender_deadline", Value: 1}}),
+		*orm.NewIndex("submission_deadline_idx", bson.D{{Key: "submission_deadline", Value: 1}}),
+		*orm.NewIndex("closing_soon_submission_idx", bson.D{
+			{Key: "submission_deadline", Value: 1},
+			{Key: "status", Value: 1},
+		}),
+		*orm.NewIndex("closing_soon_tender_deadline_idx", bson.D{
+			{Key: "tender_deadline", Value: 1},
+			{Key: "status", Value: 1},
+		}),
 		*orm.NewIndex("estimated_value_idx", bson.D{{Key: "estimated_value", Value: -1}}),
 		*orm.NewIndex("created_at_idx", bson.D{{Key: "created_at", Value: -1}}),
 		// Stable keyset pagination for default admin list (created_at desc).