Fix inconsistent spacing for edit buttons on issues and merge request page

app/assets/stylesheets/new_nav.scss

@@ -403,6 +403,7 @@ header.navbar-gitlab-new {
 }
 
 .breadcrumbs-extra {
+  display: flex;
   flex: 0 0 auto;
   margin-left: auto;
 }

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

 - if @can_bulk_update
-  = button_tag "Edit Merge Requests", class: "btn js-bulk-update-toggle"
+  = button_tag "Edit Merge Requests", class: "btn append-right-10 js-bulk-update-toggle"
 - if merge_project
   = link_to new_merge_request_path, class: "btn btn-new", title: "New merge request" do
     New merge request