Add reject step functionality to contract approval process

- Implemented rejection handling in ContractApprovalStepsCard with a modal for rejection reasons.
- Updated useContractMutations to include rejectStep mutation.
- Added REJECT_STEP URL constant for API integration.
- Enhanced ContractClearanceDetailPage to utilize linkedBookingId for improved booking handling.

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

@@ -162,6 +162,8 @@ export const URL_CONSTANTS = {
     STAFF_REJECT: (id: string) => `/contracts/${id}/staff/reject`,
     APPROVE_STEP: (id: string, stepId: string) =>
       `/contracts/${id}/approval-steps/${stepId}/approve`,
+    REJECT_STEP: (id: string, stepId: string) =>
+      `/contracts/${id}/approval-steps/${stepId}/reject`,
     CONTRACT_GENERATE: (id: string) => `/contracts/${id}/contract/generate`,
     CONTRACT_VIEW: (id: string) => `/contracts/${id}/contract/view`,
     CONTRACT_DOCUMENT: (id: string) => `/contracts/${id}/contract/document`,