In the marker chart, display the full marker name when hovering it on the left column

For marker names that are too long, we cut them so that they fit the left column.

It would be good to show the full name when hovering them. Ideally we should show all full names when hovering anywhere in the left column.

Example profile: https://share.firefox.dev/2SfOrtX

cc padenot

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-410)