Add metrics for requests and errors count

[mostafa]

Ticket(s)

• Add metrics to API #187

Description

This PR adds two new metrics for tracking the number of requests made to the API and the errors that might have occurred while accessing those endpoints.

Related PRs

N/A

Development Checklist

• I have added a descriptive title to this PR.
• I have squashed related commits together.
• I have rebased my branch on top of the latest main branch.
• I have performed a self-review of my own code.
• I have commented on my code, particularly in hard-to-understand areas.
• I have added docstring(s) to my code.
• I have made corresponding changes to the documentation (docs).
• I have added tests for my changes.
• I have signed all the commits.

Legal Checklist

• I have read the CONTRIBUTING document.
• I have read and understood the Code of Conduct.
• I have read and agreed to the Apache CLA (required).
• I have read and agreed to the LICENSE (required).