Add overview of active sessions (#3929)

* Add overview of active sessions

* Better display of browser/platform name

* Improve how browser information is stored and displayed for sessions overview

* Fix test

app/views/auth/registrations/_sessions.html.haml

@@ -0,0 +1,23 @@
+%h6= t 'sessions.title'
+%p.muted-hint= t 'sessions.explanation'
+
+%table.table.inline-table
+  %thead
+    %tr
+      %th= t 'sessions.browser'
+      %th= t 'sessions.ip'
+      %th= t 'sessions.activity'
+  %tbody
+    - @sessions.each do |session|
+      %tr
+        %td
+          %span{ title: session.user_agent }= fa_icon session_device_icon(session)
+          = ' '
+          = t 'sessions.description', browser: t("sessions.browsers.#{session.browser}"), platform: t("sessions.platforms.#{session.platform}")
+        %td
+          %samp= session.ip
+        %td
+          - if request.session['auth_id'] == session.session_id
+            = t 'sessions.current_session'
+          - else
+            %time.time-ago{ datetime: session.updated_at.iso8601, title: l(session.updated_at) }= l(session.updated_at)

app/views/auth/registrations/edit.html.haml

@@ -12,6 +12,10 @@
   .actions
     = f.button :button, t('generic.save_changes'), type: :submit
 
+%hr/
+
+= render 'sessions'
+
 - if open_deletion?
   %hr/