Gather Prometheus metrics in albs-web-server repo

[anfimovdm]

We need to integrate Prometheus into albs-web-server to collect metrics for analyzing slow code parts.
To do this, we should:

• Expose metrics at the /metrics endpoint
• Implement a base class or decorator to gather function, method, and endpoint runtime and host resource usage (host resource metrics are not a priority now)
• Integrate the monitoring class or decorator into middleware per endpoint
• Integrate the monitoring class or decorator into all dramatiq tasks in albs-web-server (create-errata, build-done, etc.)