Repository graph branch label rendering issue

Summary

If you have a commit in multiple branch heads the rendering in the repository graph is broken.

Steps to reproduce

1. Have a master branch ready
2. Create a branch
3. Put the same commit in both branches.

What is the current bug behavior?

Second branch name is rendered on the right side and therefore non readable

What is the expected correct behavior?

Maybe render both labels on the left side or both branch names in the same label

Output of checks

This bug happens on GitLab.com