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)
![Screen_Shot_2016-07-19_at_5.47.29_AM](/uploads/48e6d203de4cbe0b697280128695d980/Screen_Shot_2016-07-19_at_5.47.29_AM.png)
![Screen_Shot_2016-07-14_at_9.25.13_AM](/uploads/59118440f3e7bb903f44260abb119376/Screen_Shot_2016-07-14_at_9.25.13_AM.png)

See merge request !5244