Issue:
Bug: [REFACTOR] delete requires cvv config when merchant account is deleted



### Feature Description

Add support for removing the requires cvv config from configs table when merchant account is deleted.

### Possible Implementation

When merchant account delete request is sent, delete an entry in configs with key = '{merchant_id}_requires_cvv' 

### Have you spent some time checking if this feature request 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!

Pull request description:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [x] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
This PR includes changes for removing the requires cvv config from configs table when merchant account is deleted.

### 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 the paths where you can find config files:
1. `config`
2. `crates/router/src/configs`
3. `loadtest/config`
-->


## Motivation and Context
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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 it is an obvious bug or documentation fix
that will have little conversation).
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## How did you test it?
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Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
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![image](https://github.com/juspay/hyperswitch/assets/70657455/d9b02042-104f-4b09-a5be-f4b49591dfd9)


## 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 the submitted code
- [ ] I added unit tests for my changes where possible
- [ ] I added a [CHANGELOG](/CHANGELOG.md) entry if applicable


Testing:

![image](https://github.com/juspay/hyperswitch/assets/70657455/d9b02042-104f-4b09-a5be-f4b49591dfd9)

Patch:
diff --git a/crates/router/src/core/admin.rs b/crates/router/src/core/admin.rs
index ec229bd8a56..226d77d598e 100644
--- a/crates/router/src/core/admin.rs
+++ b/crates/router/src/core/admin.rs
@@ -491,6 +491,25 @@ pub async fn merchant_account_delete(
             .to_not_found_response(errors::ApiErrorResponse::MerchantAccountNotFound)?;
         is_deleted = is_merchant_account_deleted && is_merchant_key_store_deleted;
     }
+
+    match db
+        .delete_config_by_key(format!("{}_requires_cvv", merchant_id).as_str())
+        .await
+    {
+        Ok(_) => Ok::<_, errors::ApiErrorResponse>(()),
+        Err(err) => {
+            if err.current_context().is_db_not_found() {
+                crate::logger::error!("requires_cvv config not found in db: {err:?}");
+                Ok(())
+            } else {
+                Err(err
+                    .change_context(errors::ApiErrorResponse::InternalServerError)
+                    .attach_printable("Failed while deleting requires_cvv config"))?
+            }
+        }
+    }
+    .ok();
+
     let response = api::MerchantAccountDeleteResponse {
         merchant_id,
         deleted: is_deleted,