Milestone names get cut off in collapsed issuable sidebar

Resources

FE @annabeldunstone

Summary

If an issue is assigned to a milestone with a long name and the sidebar is collapsed, the name gets cut off.

Steps to reproduce

1. create issue
2. create milestone with long name
3. assign issue to milestone

Bug behavior

What is the current bug behavior?	What is the expected correct behavior?
The milestone name gets cut off	The milestone name is truncated and shown in the tooltip when hovering, above the time information

Also, the tooltip should be shown when hovering both the milestone name and the milestones icon (“clock”).

Possible fixes

word-wrap: break-word; text-overflow: ellipsis; overflow: hidden; margin: 0 4px;