Issue:
fix: impl `Drop` for `RedisConnectionPool`

## Type of Change
<!-- Put an `x` in the boxes that apply -->
- [x] Bugfix

## Description
<!-- Describe your changes in detail -->
This fixes #1035 

## 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
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#1035 

## How did you test it?
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Manual

## Checklist
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- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed submitted code

Resolution:
<think>
PR Context:
- Title: fix(redis): fix recreation on redis connection pool
- Merged: 2023-05-08T09:01:49Z
- Files changed: 7 files
- Commits: 1 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
This PR fixes the issue of creating multiple Redis connection pool everywhere. It provides a trait to access the interior redis connection pool.
<!-- Describe your changes in detail -->


### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(redis): fix recreation on redis connection pool (#1063)
Files to modify:


**crates/redis_interface/src/lib.rs**
  Modify existing code

**crates/router/src/core/payment_methods/cards.rs**
  Modify existing code

**crates/router/src/core/payments.rs**
  Modify existing code

**crates/router/src/core/payments/helpers.rs**
  Modify existing code

**crates/router/src/db.rs**
  Add:
    - function: private::get_redis_conn
    - impl: impl services::RedisConnInterface for MockDb

**crates/router/src/services.rs**
  Add:
    - function: private::get_redis_conn
    - trait: pub::RedisConnInterface
    - impl: impl RedisConnInterface for Store