Add breadcrumbs to User Settings sub-views

Closes #40274

app/views/doorkeeper/applications/show.html.haml

+- add_to_breadcrumbs "Applications", oauth_applications_path
+- breadcrumb_title @application.name
 - page_title @application.name, "Applications"
 - @content_class = "limit-container-width" unless fluid_layout
 

app/views/profiles/keys/show.html.haml

+- add_to_breadcrumbs "SSH Keys", profile_keys_path
+- breadcrumb_title @key.title
 - page_title @key.title, "SSH Keys"
 - @content_class = "limit-container-width" unless fluid_layout
 = render 'profiles/head'

changelogs/unreleased/40274-user-settings-breadcrumbs.yml

+---
+title: Fix breadcrumbs in User Settings
+merge_request: 16172
+author: rfwatson
+type: fixed

spec/features/profiles/keys_spec.rb

@@ -27,6 +27,7 @@ feature 'Profile > SSH Keys' do
 
       expect(page).to have_content("Title: #{attrs[:title]}")
       expect(page).to have_content(attrs[:key])
+      expect(find('.breadcrumbs-sub-title')).to have_link(attrs[:title])
     end
 
     context 'when only DSA and ECDSA keys are allowed' do

spec/features/profiles/oauth_applications_spec.rb

@@ -2,12 +2,20 @@ require 'spec_helper'
 
 describe 'Profile > Applications' do
   let(:user) { create(:user) }
+  let(:application) { create(:oauth_application, owner: user) }
 
   before do
     sign_in(user)
   end
 
   describe 'User manages applications', :js do
+    it 'views an application' do
+      visit oauth_application_path(application)
+
+      expect(page).to have_content("Application: #{application.name}")
+      expect(find('.breadcrumbs-sub-title')).to have_link(application.name)
+    end
+
     it 'deletes an application' do
       create(:oauth_application, owner: user)
       visit oauth_applications_path