Issue:
enhance(router/webhooks): expose additional incoming request details to webhooks flow

## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [x] Enhancement
- [ ] Refactoring
- [ ] Dependency updates

## Description
<!-- Describe your changes in detail -->
This PR exposes additional details about the incoming webhooks request (particularly the method) to the various connector webhook functions.

### Additional Changes
None
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

<!-- 
Provide links to the files with corresponding changes.

Following are the paths where you can find config files:
1. `config`
2. `crates/router/src/configs`
3. `loadtest/config`
-->


## Motivation and Context
<!--
Why is this change required? What problem does it solve?
If it fixes an open issue, please link to the issue here.

If you don't have an issue, we'd recommend starting with one first so the PR
can focus on the implementation (unless its an obvious bug or documentation fix
that will have little conversation).
-->
Certain connectors like Worldline will peform an initial endpoint check by making a GET request to Hyperswitch. This case needs to be handled in the connector. This PR facilitates this handling.

## 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)?
-->
Manual, compiler-guided

## 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`
- [x] I reviewed submitted code
- [ ] I added unit tests for my changes where possible
- [ ] I added a [CHANGELOG](/CHANGELOG.md) entry if applicable


Resolution:
<think>
PR Context:
- Title: enhance(router): release candidate pr for webhooks enhancement (#637)
- Merged: 2023-02-25T13:17:19Z
- Files changed: 22 files
- Commits: 5 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [x] Enhancement
- [ ] Refactoring
- [ ] Dependency updates

## Description
<!-- Describe your changes in detail -->
#637 

### Additional Changes
None
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

<!-- 
Provide links to the files with corresponding changes.

Following are the paths where you can find config files
</think>

To implement this, you'll need to modify:


(No detailed commit information available)