Ensure layout works on xs and sm screens

Add check in case buttons are not present

Apply Prettier to file

Remove unused class and div, reduce margins

See https://gitlab.com/gitlab-org/gitlab-ce/issues/30423

- Apply new styles for header, padding, border, and fonts
- Remove bootstrap 3 backward compat code

Deletes unused CSS
Moves prometheus selectors into a prometheus file

The performance dashboards will now display the data
from a set amount of time windows that are defined
on a constants file

Update metrics dashboard to support GitLab UI area chart changes

Remove jquery.scss; Combine multiple duplicate grays into global gray variables; Remove unused styles in common.scss

Adds CSS for child envrionments