Issue:
[BUG] using FRM with Signifyd throws 5xx

### Bug Description

Enabling Signifyd FRM connector for payments, and using this for a payment throws 5xx. This is due to Signifyd sending 303 which is not handled in HyperSwitch. Signifyd throws 303 as the URL is malformed.

https://api.signifyd.com//v3/orders/events/sales as opposed to https://api.signifyd.com/v3/orders/events/sales

### Expected Behavior

Calling any Signifyd API should return an expected status code.

### Actual Behavior

Calling any Signifyd API returns 303 - which is not handled in the response handler of `execute_connector_processing_step` leading to 500 - Something went wrong.

### Steps To Reproduce

1. Enable FRM via Signifyd for a payment connector
2. Create a payment
3. 5xx is thrown in API response


### 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!

Resolution:
<think>
PR Context:
- Title: fix(connector): update API endpoints for signifyd
- Merged: 2024-09-30T10:41:48Z
- Files changed: 1 files
- Commits: 1 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
Described in #5956 

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

<!--
Provide links to the files with corresponding changes.

Following are
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(connector): update API endpoints for signifyd (#5957)
Files to modify:


**crates/router/src/connector/signifyd.rs**
  Modify existing code