Implement contract document download functionality and enhance clearance review status checks

- Added methods to assert clearance reviewable, finalizable, and uploadable statuses in the ContractClearanceService.
- Introduced a new endpoint in ContractsController for downloading contract PDFs.
- Implemented download functionality in the contracts service for both backoffice and portal applications.
- Updated UI components to include download buttons for contract PDFs in relevant pages.
- Enhanced contract request and view pages to support contract document downloads.

apps/edr-freight-web/backoffice/src/constants/URLS.ts

@@ -137,6 +137,7 @@ export const URL_CONSTANTS = {
       `/contracts/${id}/approval-steps/${stepId}/approve`,
     CONTRACT_GENERATE: (id: string) => `/contracts/${id}/contract/generate`,
     CONTRACT_VIEW: (id: string) => `/contracts/${id}/contract/view`,
+    CONTRACT_DOCUMENT: (id: string) => `/contracts/${id}/contract/document`,
     CONTRACT_SIGN: (id: string) => `/contracts/${id}/contract/sign`,
     CLEARANCE_QUEUE: "/contracts/clearance/queue",
     CLEARANCE: (id: string) => `/contracts/${id}/clearance`,