[FEATURE] Add Payments - List endpoint for v2

### Feature Description

This feature adds support for retrieving a filtered list of payments via a GET /v2/payments/list endpoint where multiple values can be provided for a single filter key (e.g. connector, etc.).

### Possible Implementation

Add PaymentListFilterConstraints and payments_list_by_filter endpoint for v2

### 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!
<think>
PR Context:
- Title: feat(payments): add PaymentListFilterConstraints and payments_list_by_filter endpoint for v2
- Merged: 2025-08-21T14:04:23Z
- Files changed: 10 files
- Commits: 3 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
<!-- Describe your changes in detail -->
**Enhanced Payment Listing API with Multi-Value Filtering**

This feature adds support for retrieving a filtered list of payments via a `GET /v2/payments/list` endpoint where multiple values can be provided for a single filter key (e.g. `sta
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** feat(payments): add PaymentListFilterConstraints and payments_list_by_filter endpoint for v2 (#8794)
Files to modify:


**crates/api_models/src/payments.rs**
  Add:
    - function: private::parse_comma_separated

**crates/common_utils/src/id_type/merchant_connector_account.rs**
  Add:
    - function: private::from_str
    - impl: impl FromStr for MerchantConnectorAccountId

**crates/diesel_models/src/query/payment_attempt.rs**
  Modify existing code

**crates/hyperswitch_domain_models/src/payments/payment_attempt.rs**
  Modify existing code

**crates/hyperswitch_domain_models/src/payments/payment_intent.rs**
  Modify existing code

**crates/router/src/db/kafka_store.rs**
  Modify existing code

**crates/storage_impl/src/mock_db/payment_attempt.rs**
  Modify existing code

**crates/storage_impl/src/payments/payment_attempt.rs**
  Modify existing code

**crates/storage_impl/src/payments/payment_intent.rs**
  Modify existing code
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