Refactor tender service methods for rejected tenders and enhance unit tests

- Renamed `buildRejectedTenderIDSetForCompanies` to `buildRejectedTenderIDSetsForCompanies` to better reflect its functionality of returning a map of excluded tender IDs by company.
- Updated the implementation to return a nested map structure for better organization of excluded tender IDs per company.
- Added a new test function `TestIsRecommendedTenderExcludedForAllCompanies` to validate the visibility of tenders based on company-specific exclusions.
- Enhanced existing tests to ensure comprehensive coverage of the new logic for handling rejected tenders.

This update improves the clarity and functionality of the tender recommendation process by refining the handling of rejected tenders and expanding test coverage.

internal/tender/service.go

@@ -973,10 +973,13 @@ func (s *tenderService) Recommend(ctx context.Context, form *SearchForm, paginat
 		return nil, err
 	}
 
-	var excluded map[string]struct{}
+	var (
+		excluded          map[string]struct{}
+		excludedByCompany map[string]map[string]struct{}
+	)
 	if form.ExcludeRejectedTenders {
 		if len(companyIDs) > 0 {
-			excluded, err = s.buildRejectedTenderIDSetForCompanies(ctx, companyIDs)
+			excludedByCompany, err = s.buildRejectedTenderIDSetsForCompanies(ctx, companyIDs)
 		} else {
 			excluded, err = s.buildRejectedTenderIDSet(ctx, companyID)
 		}
@@ -999,7 +1002,11 @@ func (s *tenderService) Recommend(ctx context.Context, form *SearchForm, paginat
 		if !ok {
 			continue
 		}
-		if isRecommendedTenderExcluded(tender, tenderRef, excluded) {
+		if len(companyIDs) > 0 {
+			if isRecommendedTenderExcludedForAllCompanies(tender, tenderRef, excludedByCompany, companyIDs) {
+				continue
+			}
+		} else if isRecommendedTenderExcluded(tender, tenderRef, excluded) {
 			continue
 		}
 		if form.OnlyActiveDeadlines && !tender.IsRecommendable(now) {