Issue: [FIX] Remove ToSchema from RefundAggregateResponse and exclude it from OpenAPI documentation

### Feature Description

The RefundAggregateResponse type used by the [/refunds/aggregate](https://github.com/juspay/hyperswitch/blob/37925626e6446900f1d16e0e5f184ee472d4be3e/crates/router/src/routes/app.rs#L1004) API is currently annotated with ToSchema, which generates OpenAPI schema documentation for it. However, since this API is internal and should not be exposed to external users, the schema should not be generated or included in the OpenAPI documentation.

Current Behavior:
- The `RefundAggregateResponse` struct is annotated with ToSchema, which automatically generates OpenAPI documentation.
- This results in the exposure of internal API details that should remain hidden from external consumers.

Expected Behavior:
- Remove the `ToSchema` derive macro from the RefundAggregateResponse struct.
- Ensure that this struct and its associated API are excluded from OpenAPI documentation generation.

### Possible Implementation


The Api [refunds/aggregate](https://github.com/juspay/hyperswitch/blob/37925626e6446900f1d16e0e5f184ee472d4be3e/crates/router/src/core/refunds.rs#L1098) returns `RefundAggregateResponse`
The following code should be modified to remove ToSchema and update the OpenAPI documentation accordingly:
```
#[derive(Clone, Debug, serde::Serialize, ToSchema)] 
pub struct RefundAggregateResponse {
    /// The list of refund status with their count
    pub status_with_count: HashMap<enums::RefundStatus, i64>,
}
```

Tasks:
- Remove the ToSchema derive macro from the RefundAggregateResponse struct.
- Remove any references to RefundAggregateResponse from openapi.rs to ensure it is not documented.
- Test to verify that this type is no longer included in the OpenAPI schema.

Additional Context:
Since the `/refunds/aggregate` API is for internal use only, removing the OpenAPI schema ensures that this internal API remains undocumented for merchants.

### Have you spent some time checking if this feature request has been raised before?

- [X] I checked and didn't find a similar issue

### Submission Process:
- Ask the maintainers for assignment of the issue, you can request for assignment by commenting on the issue itself.
- Once assigned, submit a pull request (PR).
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Resolution: <think>
PR Context:
- Title: fix(refunds): remove to schema from refund aggregate response and exclude it from open api documentation
- Merged: 2024-11-05T09:26:13Z
- Files changed: 5 files
- Commits: 11 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
<!-- Describe your changes in detail -->
Removed all the openapi references to `RefundAggregateResponse`.

1. Removed `ToSchema` trait for `RefundAggregateResponse`.
2. Removed references from `openapi` and `openapi_v2` to `RefundAggregateResponse`.
3. Generated new `openapi_spec
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(refunds): remove to schema from refund aggregate response and exclude it from open api documenta
Files to modify:


**crates/api_models/src/refunds.rs**
  Modify existing code

**crates/openapi/src/openapi.rs**
  Modify existing code

**crates/openapi/src/openapi_v2.rs**
  Modify existing code