Resolve "Improve visibility of deploy boards"

What does this MR do?

1. Receives deploy boards data in the environments' endpoint.

2. State is now sent in the API response:

3. Loading spinner will be rendered when status is loading 1. Won't be visible every time the user clicks, only when API sends it as loading.

4. Empty state will be rendered when status is not_found

5. Deploy board instances will be rendered when status is found

6. All deploy boards are open by default

7. Deploy board error state was removed since only one request is now made, it falls back to the main error.

Screenshots (if relevant)

Screen_Recording_2017-09-21_at_02.41_PM

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #3328 (closed)