Create landing page for curation trails

[mahdiyari]

Each curation trail will have a landing page to introduce the trail Link of the landing page can be shared with other users to follow the curation trail

• [x] Add routing to support /curation-trail/@username
• [x] Create TrailPageComponent
• [x] Add user avatar image
• [x] Add account balance (steem, sbd, sp and delegations)
• [x] Add trail description, followers, website, 7 days curation reward and follow/unfollow (+ enable/disable?) buttons
• [x] Add extra markdown text for premium users (will be activated after developing payment system)
• [x] Redirect users after login to where they clicked on the login button
• [ ] ~Add settings for trail followers (weight, delay, voting method, enable/disable, ...) + bulk settings~
• [ ] ~Add settings for trail owners (creating and editing)~

Edit: The last two takes too much work! it is better to open a pull request for each one.