Fix follow/unfollow buttons on public profile (fixes #7036) (#7040)

* Fix follow/unfollow buttons on public profile

- Present non-logged users with web+mastodon:// URLs for remote accounts
- Present logged-in users with appropriate links (authorize_follows and
  remote_unfollows) for remote accounts

* Do not cache rendered cards if user is logged in

app/views/remote_unfollows/_card.html.haml

@@ -0,0 +1,13 @@
+.account-card
+  .detailed-status__display-name
+    %div
+      = image_tag account.avatar.url(:original), alt: '', width: 48, height: 48, class: 'avatar'
+
+    %span.display-name
+      - account_url = local_assigns[:admin] ? admin_account_path(account.id) : TagManager.instance.url_for(account)
+      = link_to account_url, class: 'detailed-status__display-name p-author h-card', target: '_blank', rel: 'noopener' do
+        %strong.emojify= display_name(account)
+        %span @#{account.acct}
+
+  - if account.note?
+    .account__header__content.emojify= Formatter.instance.simplified_format(account)