FIX: Improve top links section from user summary (#15675)

* Do not extract links for hotlinked images
* Include only links that have been clicked at least once in user
summary

spec/models/user_summary_spec.rb

@@ -93,4 +93,11 @@ describe UserSummary do
     expect(summary.top_categories.first[:topic_count]).to eq(1)
     expect(summary.top_categories.first[:post_count]).to eq(1)
   end
+
+  it "does not include summaries with no clicks" do
+    post = Fabricate(:post, raw: "[example](https://example.com)")
+    TopicLink.extract_from(post)
+    summary = UserSummary.new(post.user, Guardian.new)
+    expect(summary.links.length).to eq(0)
+  end
 end