Issue: [BUG] There is a bug when the webhook response comes from ucs

### Bug Description

There is a bug when the webhook response comes from ucs,
the code was not able to deserialize the response

### Expected Behavior

webhook response form ucs should be handle using ucs logic

### Actual Behavior

a webhook failed

### Steps To Reproduce

Provide an unambiguous set of steps to reproduce this bug. Include code or configuration to reproduce, if relevant.
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2. Click on '....'
3. Scroll down to '....'


### 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?

None

Resolution: <think>
PR Context:
- Title: fix: Resolved issue of webhooks response from ucs
- Merged: 2025-08-29T15:11:29Z
- Files changed: 6 files
- Commits: 14 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
while handling the response of UCS for webhooks Hyperswitch used to use the existing connector code (Psync's Handle Respnse) which gave error for UCS response so fixed this issue.
Closes #9027 

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifi
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix: Resolved issue of webhooks response from ucs (#9021)
Files to modify:


**crates/api_models/src/webhooks.rs**
  Add:
    - function: pub::from_ucs_event_type
    - impl: impl IncomingWebhookEvent

**crates/common_enums/src/enums.rs**
  Modify existing code

**crates/router/src/core/payments.rs**
  Modify existing code

**crates/router/src/core/unified_connector_service/transformers.rs**
  Modify existing code

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

**crates/router/src/services/api.rs**
  Add:
    - function: private::handle_ucs_response