Issue:
[FEATURE]: [PayU] 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?


Resolution:
<think>
PR Context:
- Title: feat(connector): [PayU] Use connector_request_reference_id
- Merged: 2024-10-25T11:31:30Z
- Files changed: 1 files
- Commits: 3 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [x] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
Add connector_request_reference_id support for PayU

- Used `extOrderId` as the reference id based on the [PayU documentation](https://developers.payu.com/europe/api/#tag/Order/operation/create-an-order) reference:

![image](https://github.com/user-attachments/assets/f730028d-1fa4
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** feat(connector): [PayU] Use connector_request_reference_id (#6360)
Files to modify:


**crates/hyperswitch_connectors/src/connectors/payu/transformers.rs**
  Modify existing code