Create a service method to fetch the reviews done by one user

Summary

Call The GitLab API to retrieve all the reviews a user has made. This call should be made per project and per group.

Reviews include the following:

• comments and discussions on issues and merge requests
• merge request approvals

Checklist

• retrieve all comments and discussions on issues and merge requests that a user was involved with (per project and per group)
• retrieve all merge request approvals made by one user (per project and per group)

Implementation details

• return from the method only the relevant data for displaying and filtering
• you can return a record for now