[BUG] mandate details are not persisted for Adyen connector

### Bug Description

This is specific to Adyen's connector integration.

In case mandate details were not present in the response of payment sync with Adyen, these details are sent through webhooks. However, these details are not being persisted in DB leading to MIT failures.

### Expected Behavior

Mandate details sent in the webhook's request should be persisted in payment_methods table for future MITs

### Actual Behavior

Mandate details sent in the webhook's request are not persisted in `payment_methods` table.

### Steps To Reproduce

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### Context For The Bug

_No response_

### Environment

Are you using hyperswitch hosted version? Yes/No
If yes, please provide the value of the `x-request-id` response header to help us debug your issue.

If not (or if building/running locally), please provide the following details:
1. Operating System or Linux distribution:
2. Rust version (output of `rustc --version`): ``
3. App version (output of `cargo r --features vergen -- --version`): ``


### Have you spent some time checking if this bug 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!
<think>
PR Context:
- Title: feat(webhooks): adyen - consume and update connector's network_transaction_id in payment_methods
- Merged: 2024-12-05T13:34:59Z
- Files changed: 7 files
- Commits: 10 commits

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

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

## Description
Described in #6719 

This PR introduces below changes
- `get_network_txn_id` fn in IncomingWebhook trait
- implement this new fn for Adyen for retrieving the network txn ID
- consume this fn in core flows for updating `network_transaction_id` in `payment_methods` table

### Add
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** feat(webhooks): adyen - consume and update connector's network_transaction_id in payment_methods (#6
Files to modify:


**crates/diesel_models/src/payment_method.rs**
  Modify existing code

**crates/hyperswitch_domain_models/src/router_flow_types/webhooks.rs**
  Add:
    - function: pub::new
    - function: pub::get_id
    - struct: pub::ConnectorNetworkTxnId
    - impl: impl ConnectorNetworkTxnId

**crates/hyperswitch_interfaces/src/webhooks.rs**
  Add:
    - function: private::get_network_txn_id

**crates/router/src/connector/adyen.rs**
  Add:
    - function: private::get_network_txn_id

**crates/router/src/connector/adyen/transformers.rs**
  Modify existing code

**crates/router/src/core/webhooks/incoming.rs**
  Modify existing code

**crates/router/src/services/connector_integration_interface.rs**
  Add:
    - function: private::get_network_txn_id
{"issue_number": 6719, "pr_number": 6738, "commits_count": 1, "files_changed": 7, "response_length": 1694, "file_count": 9, "needs_breakdown": false}