[Backend] Support the ability to know why a group of charts have no data
Backend Issue for https://gitlab.com/gitlab-org/gitlab-ce/issues/64612
Problem to solve
Right now, we don't have very granular error messages on charts - we simply say 'no data to display' if there is any error in displaying the charts.
To improve this messaging, it would be good to figure out how to get more granular information about why the chart display is failing, for example: group is not configured, GitLab couldn't communicate with the user's system, etc. This will better help users to troubleshoot why their graphs aren't working.
Intended users
Further details
Proposal
We need to pass no data
reasons to the frontend.
Permissions and Security
Documentation
Testing
What does success look like, and how can we measure that?
Links / references
Edited by Adriel Santiago