Issue:
[BUG] Add metrics in router scheduler flow as it is being ignored now

### Bug Description

Router is not maintaining any metrics about the task added in scheduler. this has to be fixed
File: crates/router/src/core/payments/helpers.rs
Method: add_domain_task_to_pt

### Expected Behavior

Metrics has to be added to know the TASKS_ADDED_COUNT and TASKS_RESET_COUNT

### Actual Behavior

Currently those are not available

### Steps To Reproduce

NA

### Context For The Bug

_No response_

### Environment

NA

### Have you spent some time checking if this bug 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?

None

Resolution:
<think>
PR Context:
- Title: fix(metrics): Add TASKS_ADDED_COUNT and TASKS_RESET_COUNT metrics in router scheduler flow
- Merged: 2024-01-18T10:29:35Z
- Files changed: 8 files
- Commits: 9 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Bugfix

## Description
<!-- Describe your changes in detail -->
Currently `TASKS_ADDED_COUNT` and `TASKS_RESET_COUNT` metrics does not exist in router to track the tasks added in scheduler. This PR aims at adding that.  
Closes #2090

## Motivation and Context
<!--
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 r
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(metrics): Add TASKS_ADDED_COUNT and TASKS_RESET_COUNT metrics in router scheduler flow (#3189)
Files to modify:


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

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

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

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

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

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

**crates/router/src/workflows/api_key_expiry.rs**
  Modify existing code

**crates/scheduler/src/metrics.rs**
  Modify existing code