fix(metrics): Add TASKS_ADDED_COUNT and TASKS_RESET_COUNT metrics in router scheduler flow

[pixincreate]

Type of Change

• Bugfix

Description

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

We need to track the tasks added in scheduler.

How did you test it?

Did a few payments (Ran Stripe and Volt collection a few times):

Local setup:

Modify 3 files:

• docker-compose.yml: Expose the otel-collector port by replacing "4317" with "4317:4317"
• development.toml: Enable logging by setting metrics_enabled to true and otel_exporter_otlp_endpoint to http://localhost:4317
• otel-collector.yml: Add logging in exporters of pipeline service: [prometheus, logging] instead of [prometheus]
• Open a terminal window, start server by executing: cargo r
• Create another terminal window for psql, execute:

   psql hyperswitch_db
   \x
   \dt
   table process_tracker;
  

• Create another 3 terminal windows. One for consumer, another for producer and another for Grafana. Execute:

   # In consumer terminal window
   SCHEDULER_FLOW=consumer cargo r --bin scheduler 
   # In producer terminal window
   SCHEDULER_FLOW=producer cargo r --bin scheduler
   # In Grafana terminal window
   docker compose up -d grafana prometheus otel-collector
  

• Execute curl telnet://localhost:4317 in yet another terminal window to see if this URL can be accessed or not
• Grafana username/password - admin/admin

  incase reset is required, execute in terminal:
  grafana-cli admin reset-admin-password <new-password>

In env:

• Open Grafana > VM Single > Metric:router_TASKS_ADDED_COUNT_total, label:job=router > Run Query

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible
• I added a CHANGELOG entry if applicable