Describe the issue

Using a legend with 2 or more identical labels causes the sizing logic to fail and render a very narrow legend.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/confident-http-qv2ks?file=/src/App.tsx
2. Notice the legend label is about 1 px width
3. Toggle off the legendMaxDepth option and the width with return to the correct value.

Expected behaviour
Legend sizes correctly

Screenshots

Kibana Cross Issues

elastic/kibana#125129

Checklist

• The proper chart type label has been added (e.g. :xy, :partition)
• The proper feature labels have been added (e.g. :interactions, :axis)
• Every related Kibana issue is listed under Kibana Cross Issues list and the kibana cross issue tag is applied