Resolve "Move Build badges settings to Builds page (or Builds settings)"
## What does this MR do?
Removes pipeline settings section from project settings & creates a new pipelines settings page
Adds builds badge to pipelines settings page & removes badge page
## Are there points in the code the reviewer needs to double check?
All Rails updates -> particularly `builds_controller.rb` and `routes`
Spacing needs to be updated across all settings pages and will be in a separate MR (https://gitlab.com/gitlab-org/gitlab-ce/issues/19827)
## What are the relevant issue numbers?
Closes #15343
Part of #18920
## Screenshots (if relevant)
See merge request !5244
