Don't wrap thread header above md screens

[nicolaskempf57]

Header and copy buttons aren't wrapped to a new line on lg screen and above. They are wrapped for md screens and below. Here are some screenshots to see the wrap / nowrap for :

1. desktop
2. lg screen just above md
3. md screen

We can add more changes if we want to :

• The current text-wrap is the browser default, we can update it if we want to keep the link on a single line for example.
• There is no col with width in this PR (like col-8), we can use this solution if we want more control about the ratio between title and link.

Close datagouv/data.gouv.fr#670

[maudetes]

I think we're all good :)