Add front_matter_controls.vue component
See the related planning issue for additional context: #233472 (closed)
Ref design: #235921[Direction_-_20200824.png]
![#235921[Direction_-_20200824.png]](https://gitlab.com/gitlab-org/gitlab/-/issues/235921/designs/Direction_-_20200824.png){kind=link}
Edited by Derek Knox
See the related planning issue for additional context: #233472 (closed)
Ref design: #235921[Direction_-_20200824.png]