refactor: improve http error handling in REST API endpoints

[t1agob]

Description

Refactor HTTP error handling in REST API endpoints for backend routes. The new payload expected when an HTTP error is captured looks like the following.

{
    "errors": [
        "Failed to get change events for service. Caller is not authorized to view the requested resource."
    ]
}

This helps in providing a better user experience to the user from a frontend perspective.

Issue number: N/A

Type of change

• [ ] New feature (non-breaking change which adds functionality)
• [x] Fix (non-breaking change which fixes an issue)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• [x] I have performed a self-review of this change
• [x] Changes have been tested
• [x] Changes are documented
• [x] Changes generate no new warnings
• [x] PR title follows conventional commit semantics

If this is a breaking change 👇

• [ ] I have documented the migration process
• [ ] I have implemented necessary warnings (if it can live side by side)

Acknowledgement

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

Disclaimer: We value your time and bandwidth. As such, any pull requests created on non-triaged issues might not be successful.