feat : ajout d'un champ commentaire sur les contrats + correction de plusieurs bugs

frontend/services/dto/employee.ts

@@ -8,6 +8,7 @@ export type ContractHistoryItem = {
   contractNature: 'CDI' | 'CDD' | 'INTERIM'
   startDate: string
   endDate?: string | null
+  comment?: string | null
 }
 
 export type Employee = {

frontend/services/dto/work-hour.ts

@@ -15,6 +15,7 @@ export type WorkHour = {
   isPresentAfternoon?: boolean
   isSiteValid?: boolean
   isValid?: boolean
+  updatedAt?: string | null
 }
 
 export type WorkHourEntryPayload = {