fix(order): searchable fields (#9493)

FIXES: TRI-353

integration-tests/http/__tests__/order/admin/order.spec.ts

@@ -140,6 +140,23 @@ medusaIntegrationTestRunner({
           .order
       })
 
+      it("should find the order querying it by number", async () => {
+        const userEmail = "tony@stark-industries.com"
+
+        const response = (
+          await api.get(`/admin/orders/?q=non-existing`, adminHeaders)
+        ).data
+
+        expect(response.orders).toHaveLength(0)
+
+        const response2 = (
+          await api.get(`/admin/orders/?fields=+email&q=@stark`, adminHeaders)
+        ).data
+
+        expect(response2.orders).toHaveLength(1)
+        expect(response2.orders[0].email).toEqual(userEmail)
+      })
+
       it("should only create fulfillments grouped by shipping requirement", async () => {
         const {
           response: { data },