Bug: [FEATURE]: [Iatapay] Use `connector_request_reference_id` as reference to the connector



### :memo: Feature Description 

- We transmit our reference id from Hyperswitch to the connector, enabling merchants to subsequently locate the payment within the connector dashboard.
- Presently, there is a lack of uniformity in this process, as some implementations employ `payment_id` while others utilize `attempt_id`.
- This inconsistency arises from the fact that `payment_id` and `attempt_id` correspond to two distinct entities within our system.

### :hammer: Possible Implementation 

- To mitigate this confusion, we've introduced a new field called `connector_request_reference_id` in our RouterData. 
- This id should replace them as a reference id to the connector for payment request. 
- One might need to have exposure to api docs of the connector for which it is being implemented.
- You can check this PR for further reference https://github.com/juspay/hyperswitch/pull/2052

:bookmark: Note : All the changes needed should be contained within `hyperswitch/crates/router/src/connector/`


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

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

### :package: Have you read the Contributing Guidelines?

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

### :sparkles: Are you willing to submit a PR?

diff --git a/crates/router/src/connector/iatapay/transformers.rs b/crates/router/src/connector/iatapay/transformers.rs
index f98798fe5be..d4731b024c8 100644
--- a/crates/router/src/connector/iatapay/transformers.rs
+++ b/crates/router/src/connector/iatapay/transformers.rs
@@ -110,7 +110,7 @@ impl TryFrom<&types::PaymentsAuthorizeRouterData> for IatapayPaymentsRequest {
             utils::to_currency_base_unit_asf64(item.request.amount, item.request.currency)?;
         let payload = Self {
             merchant_id: IatapayAuthType::try_from(&item.connector_auth_type)?.merchant_id,
-            merchant_payment_id: Some(item.payment_id.clone()),
+            merchant_payment_id: Some(item.connector_request_reference_id.clone()),
             amount,
             currency: item.request.currency.to_string(),
             country: country.clone(),

## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [x] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
fixes #2302 

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

## How did you test it?
<!--
Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
-->
Make any Payment for connector Iatapay and see that you are getting "reference_id" field in the logs of payment request.

## 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`
- [ ] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible
- [ ] I added a [CHANGELOG](/CHANGELOG.md) entry if applicable
