Render wiki like issues in search results

Previously we used to render these exactly the same as code results and
only show a few lines of code. Since the wiki is more like human
readable text then it makes more sense to just render it as text in
paragraph form than lines of code. This also allows highlighting to pick
up single words being matched.

Basically this is done by using the same styling we do on issue search
results. It does come with the downside that we truncate the text so
highlighting matching words later in the wiki won't be visible in the
snippet anymore.

app/views/search/results/_wiki_blob.html.haml

 - project = wiki_blob.project
 - wiki_blob_link = project_wiki_path(project, wiki_blob.basename)
 
-= render partial: 'search/results/blob_data', locals: { blob: wiki_blob, project: project, path: wiki_blob.path, blob_link: wiki_blob_link }
+%div{ class: 'search-result-row gl-pb-3! gl-mt-5 gl-mb-0!' }
+  %span.gl-display-flex.gl-align-items-center
+    = link_to wiki_blob_link, data: { track_event: 'click_text', track_label: "wiki_title", track_property: 'search_result' }, class: 'gl-w-full' do
+      %span.term.str-truncated.gl-font-weight-bold= ::Gitlab::Git::Wiki::GollumSlug.canonicalize_filename(wiki_blob.path)
+  .description.term.col-sm-10.gl-px-0
+    = simple_search_highlight_and_truncate(wiki_blob.data, @search_term)

changelogs/unreleased/260340-wiki-render-like-issues.yml

+---
+title: Improve the look of wikis in search results
+merge_request: 47470
+author:
+type: changed

ee/spec/features/search/elastic/global_search_spec.rb

@@ -164,15 +164,14 @@ RSpec.describe 'Global elastic search', :elastic, :sidekiq_inline do
       ensure_elasticsearch_index!
     end
 
-    it "finds files" do
+    it "finds wiki pages" do
       visit dashboard_projects_path
 
       submit_search('term')
       select_search_scope('Wiki')
 
-      expect(page).to have_selector('.file-content .code')
-
-      expect(page).to have_selector("span.line[lang='markdown']")
+      expect(page).to have_selector('.search-result-row .description', text: '# term')
+      expect(page).to have_link('test')
     end
   end
 

ee/spec/features/search/elastic/group_search_spec.rb

@@ -71,12 +71,12 @@ RSpec.describe 'Group elastic search', :js, :elastic, :sidekiq_might_not_need_in
       ensure_elasticsearch_index!
     end
 
-    it 'finds pages' do
+    it 'finds wiki pages' do
       submit_search('term')
       select_search_scope('Wiki')
 
-      expect(page).to have_selector('.file-content .code')
-      expect(page).to have_selector('span.line[lang="markdown"]')
+      expect(page).to have_selector('.search-result-row .description', text: '# term')
+      expect(page).to have_link('test')
     end
   end