Resolve "Link from build page to its pipeline"

## What does this MR do?

Adds references and links to a build's pipeline within both individual build pages and the build index.

## Are there points in the code the reviewer needs to double check?

Nothing springs to mind

## Why was this MR needed?

See #22307

## Screenshots (if relevant)

![Screen_Shot_2016-10-24_at_3.45.39_PM_copy](/uploads/e6e8745a0a39d8b71c007e7df5fbd051/Screen_Shot_2016-10-24_at_3.45.39_PM_copy.png)

![Screen_Shot_2016-10-24_at_3.46.03_PM_copy](/uploads/3e2eb656347751f10bf62891b56ebcc7/Screen_Shot_2016-10-24_at_3.46.03_PM_copy.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- Tests
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

Closes #22307

See merge request !7082