Issue:
feat(payments): show aggregate count of refund status

Resolution:
<think>
PR Context:
- Title: feat(refunds): Refunds aggregate api
- Merged: 2024-09-12T13:57:33Z
- Files changed: 14 files
- Commits: 24 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [x] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
Added new api for refunds status aggregate

### Additional Changes

- [x] 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 ch
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** feat(refunds): Refunds aggregate api (#5795)
Co-authored-by: hyperswitch-bot[bot] <148525504+hypersw
Files to modify:


**crates/api_models/src/events/refund.rs**
  Add:
    - function: private::get_api_event_type
    - impl: impl ApiEventMetric for RefundAggregateResponse

**crates/api_models/src/refunds.rs**
  Add:
    - struct: pub::RefundAggregateResponse

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

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

**crates/router/src/core/refunds.rs**
  Add:
    - function: pub::get_aggregates_for_refunds

**crates/router/src/db/kafka_store.rs**
  Add:
    - function: private::get_refund_status_with_count

**crates/router/src/db/refund.rs**
  Add:
    - function: private::get_refund_status_with_count
    - function: private::get_refund_status_with_count
    - function: private::get_refund_status_with_count

**crates/router/src/routes/app.rs**
  Modify existing code

**crates/router/src/routes/lock_utils.rs**
  Modify existing code

**crates/router/src/routes/refunds.rs**
  Add:
    - function: pub::get_refunds_aggregates

**crates/router/src/types/storage/refund.rs**
  Add:
    - function: private::get_refund_status_with_count

**crates/router_env/src/logger/types.rs**
  Modify existing code