Refactor Tender Approval Logic and Update Statistics Structure

- Modified the Reject method in the TenderApproval entity to reset the SubmissionMode field upon rejection, ensuring proper state management.
- Simplified the TenderApprovalStatsResponse and CompanyTenderApprovalStatsResponse structures by removing unnecessary fields related to submission modes, streamlining the data model for tender approval statistics.
- Updated the GetTenderApprovalStats and GetCompanyTenderApprovalStats methods in the repository to reflect the changes in the statistics structure, enhancing clarity and maintainability.
- These adjustments improve the overall functionality and data handling of the tender management system.

internal/tender_approval/entity.go

@@ -145,6 +145,7 @@ func (ta *TenderApproval) Approve() {
 // Reject rejects the tender with a reason
 func (ta *TenderApproval) Reject() {
 	ta.Status = ApprovalStatusRejected
+	ta.SubmissionMode = ""
 	ta.CreatedAt = time.Now().Unix()
 }