Issue:
Bug:  [FEATURE] : [Iatapay] mask pii information in connector request and response 



### Feature Description

Mask pii information passed and received in the connector request and response

### Possible Implementation

Refactor all sensitive response and request fields secret

### Have you spent some time checking if this feature request has been raised before?

- [X] I checked and didn't find a similar issue

### Have you read the Contributing Guidelines?

- [X] I have read the [Contributing Guidelines](https://github.com/juspay/hyperswitch/blob/main/docs/CONTRIBUTING.md)

### Are you willing to submit a PR?

Yes, I am willing to submit a PR!

Pull request description:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [x] Enhancement
- [x] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
Mask pii information passed and received in the connector request and response for Iatapay.

## Test Case
<!--
Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
-->
1. UPI Payment Create
```
curl --location 'http://localhost:8080/payments' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--header 'api-key:{{api_key}}' \
--data-raw '{
  "amount": 5000,
  "currency": "INR",
  "confirm": true,
  "capture_method": "automatic",
  "capture_on": "2022-09-10T10:11:12Z",
  "amount_to_capture": 5000,
  "customer_id": "IatapayCustomer",
  "email": "guest@example.com",
  "name": "John Doe",
  "phone": "999999999",
  "phone_country_code": "+1",
  "description": "Its my first payment request",
  "authentication_type": "no_three_ds",
  "return_url": "https://google.com",
  "payment_method": "upi",
  "payment_method_type": "upi_collect",
  "payment_method_data": {
    "upi": {
      "vpa_id": "successtest@iata"
    }
  },
  "billing": {
    "address": {
      "line1": "1467",
      "line2": "Harrison Street",
      "line3": "Harrison Street",
      "city": "San Fransico",
      "state": "California",
      "zip": "94122",
      "country": "IN",
      "first_name": "joseph",
      "last_name": "Doe"
    },
    "phone": {
      "number": "8056594427",
      "country_code": "+91"
    }
  },
  "shipping": {
    "address": {
      "line1": "1467",
      "line2": "Harrison Street",
      "line3": "Harrison Street",
      "city": "San Fransico",
      "state": "California",
      "zip": "94122",
      "country": "US",
      "first_name": "joseph",
      "last_name": "Doe"
    },
    "phone": {
      "number": "8056594427",
      "country_code": "+91"
    }
  },
  "statement_descriptor_name": "joseph",
  "statement_descriptor_suffix": "JS",
  "metadata": {
    "udf1": "value1",
    "new_customer": "true",
    "login_date": "2019-09-10T10:11:12Z"
  }
}'
```

2. Check if all the sensitive data in the `masked_response` is masked

```
curl --location '{{base_url}}/analytics/v1/connector_event_logs?type=Payment&payment_id={{payment_id}}' \
--header 'sec-ch-ua: "Not A(Brand";v="99", "Google Chrome";v="121", "Chromium";v="121"' \
--header 'sec-ch-ua-mobile: ?0' \
--header 'authorization: Bearer JWT_token' \
--header 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36' \
--header 'Content-Type: application/json' \
--header 'Referer: https://integ.hyperswitch.io/' \
--header 'api-key: {{api-key}}' \
--header 'sec-ch-ua-platform: "macOS"'
```
Expected Response

```
\"masked_response\":\"{\\\"status\\\":\\\"CREATED\\\",\\\"iataPaymentId\\\":\\\"PH3WO013A5QTQ\\\",\\\"iataRefundId\\\":null,\\\"merchantId\\\":\\\"*** alloc::string::String ***\\\",\\\"merchantPaymentId\\\":\\\"pay_JBrbR1SRhIJ1BivCvB60_1\\\",\\\"amount\\\":50.0,\\\"currency\\\":\\\"INR\\\",\\\"checkoutMethods\\\":{\\\"redirect\\\":{\\\"redirectUrl\\\":\\\"https://sandbox.iata-pay.iata.org/api/v1/payments/PH3WO013A5QTQ/checkout/redirect\\\"}},\\\"failureCode\\\":null,\\\"failureDetails\\\":null}
```


## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible
- [ ] I added a [CHANGELOG](/CHANGELOG.md) entry if applicable


Testing:

Patch:
diff --git a/crates/router/src/connector/iatapay/transformers.rs b/crates/router/src/connector/iatapay/transformers.rs
index 55778af882b..b2507661395 100644
--- a/crates/router/src/connector/iatapay/transformers.rs
+++ b/crates/router/src/connector/iatapay/transformers.rs
@@ -261,7 +261,7 @@ pub struct IatapayPaymentsResponse {
     pub status: IatapayPaymentStatus,
     pub iata_payment_id: Option<String>,
     pub iata_refund_id: Option<String>,
-    pub merchant_id: Option<String>,
+    pub merchant_id: Option<Secret<String>>,
     pub merchant_payment_id: Option<String>,
     pub amount: f64,
     pub currency: String,
@@ -428,7 +428,7 @@ pub struct RefundResponse {
     iata_payment_id: Option<String>,
     merchant_payment_id: Option<String>,
     payment_amount: Option<f64>,
-    merchant_id: Option<String>,
+    merchant_id: Option<Secret<String>>,
     account_country: Option<String>,
 }