Extract merge_requests.scss into page specific CSS

app/assets/stylesheets/_page_specific_files.scss

app/assets/stylesheets/page_bundles/merge_request.scss

app/views/projects/commits/show.html.haml

app/views/projects/issues/new.html.haml

app/views/projects/jobs/index.html.haml

app/views/projects/jobs/show.html.haml

app/views/projects/merge_requests/conflicts/show.html.haml

app/views/projects/merge_requests/creations/new.html.haml

app/views/projects/merge_requests/diffs.html.haml

app/views/projects/merge_requests/index.html.haml

app/views/projects/merge_requests/show.html.haml

app/views/projects/pipeline_schedules/index.html.haml

app/views/projects/pipelines/show.html.haml

config/application.rb

...pp/views/projects/security/vulnerabilities/show.html.haml