finish bills , po , jobcards relational fields creation

packages/api/src/clients/purchase-orders.ts

@@ -14,4 +14,9 @@ export class PurchaseOrdersClient extends CrudClient<
     constructor(baseUrl?: string, defaultOptions?: ApiClientOptions) {
         super(baseUrl, defaultOptions, PURCHASE_ORDER_ROUTES.INDEX, PURCHASE_ORDER_ROUTES.BY_ID)
     }
+
+    async getById(id: string) {
+        const res=  await this.list({query: { id }})
+        return { ...res, data: (res as any)?.data[0] ?? res }
+    }
 }