Pipeline badge improvements

What does this MR do?

Fixes gitlab-org/gitlab-ce#15582

Screenshots (if relevant)

I'd like @filipa to approve the width of the new badge. Given pipeline has more characters than build, I had to widen it. Now the width matches the coverage badge width. This was done as it would be nice if those are in either a table or list format.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together