Add possibility to see user's subscriptions

As a user I don't like spam, so I want to be able to manage all my subscriptions from one place
So, add a list of all my subscriptions, branch and topics, with short description (what does it mean if I subscribe to a branch/topic)
Acceptance criterias:

• create submenu 'Subscription' in user's profile;
• create submenu 'Subscription' in dropdown in user's profile;
• user should have an ability to view all his subscriptions via profile or dropdown in user's profile;
• user should have an ability to manage all his subscriptions. There are: delete a subscription, subscribe on a topic with notification, subscribe on a topic without notification, unsubscribe to a topic;
• in 'Subscription' menu of user's profile user should see a name of topics, author's name, last message and date when it was leave;
• create checkbox near to each topics for choice topic to manage it;
• create dropdown menu below a list of subscriptions with points:
  • delete a subscription
  • get a notification on email
  • no email notification
  • unsubscribe to topic;
• user should be redirected to first post of topic if he clicks on topic's link;
• user should bу redirected to last post of topic if he clicks on last message link;