Feature: Prometheus Middleware

[roma-frolov]

Description

Implemented Prometheus middleware for all brokers.

It seems to me that the getting-started documentation for prometheus middlewares (index.md) is not entirely complete. I would be glad to receive suggestions on what I would like to see in the documentation for this implementation.

Fixes #1665

Type of change

• [x] Documentation (typos, code examples, or any documentation updates)
• [x] Bug fix (a non-breaking change that resolves an issue)
• [x] New feature (a non-breaking change that adds functionality)
• [x] This change requires a documentation update

Checklist

• [x] My code adheres to the style guidelines of this project (scripts/lint.sh shows no errors)
• [x] I have conducted a self-review of my own code
• [x] I have made the necessary changes to the documentation
• [x] My changes do not generate any new warnings
• [x] I have added tests to validate the effectiveness of my fix or the functionality of my new feature
• [x] Both new and existing unit tests pass successfully on my local environment by running scripts/test-cov.sh
• [x] I have ensured that static analysis tests are passing by running scripts/static-analysis.sh
• [x] I have included code examples to illustrate the modifications