Integrate new vue+vuex code base with new API and remove old haml code

With https://gitlab.com/gitlab-org/gitlab-ce/issues/50101, we created a vue and vuex code base for the job show page. We now need to integrate it with the new API and deprecate the HAML+old JS code.

TODO:

TODO's

• Create main Job app

  • Delete old header component, use ci_header directly
  • Remove mediator
  • Remove service
  • Remove loading icon from sidebar
  • Update sidebar HTML to match haml

• Job Log

  • Handle Scroll behavior
    • Automatically scrolls to bottom after trace is loaded
    • Scroll down button shows animation while automatic scroll is active
    • While log is not complete, if user hasn't scrolled, keep scrolling to the bottom every time we receive more log
    • Stop scrolling down automatically after user has scrolled once
  • Top bar needs affix
  • Scroll down animation svg is not working in vue because the icon is not the same and classes are now dynamic.

• Make scroll behavior reusable in master so we can use it here: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21931

• Handle component's adjustments to match the API https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21930

• Empty states illustrations path need to be updated on BE to work with Vue

• Missing has_trace check: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21950

• Sidebar collapse behavior

• Fetch stages from pipeline.path

• Fetch stages content from pipeline.path/stage.json?stage=$STAGENAME&retried=1

• Stuck block

• Erased block

• Environments block

• Runners block