Lists (#5703)

* Add structure for lists

* Add list timeline streaming API

* Add list APIs, bind list-account relation to follow relation

* Add API for adding/removing accounts from lists

* Add pagination to lists API

* Add pagination to list accounts API

* Adjust scopes for new APIs

- Creating and modifying lists merely requires "write" scope
- Fetching information about lists merely requires "read" scope

* Add test for wrong user context on list timeline

* Clean up tests

app/controllers/api/v1/timelines/home_controller.rb

@@ -31,7 +31,7 @@ class Api::V1::Timelines::HomeController < Api::BaseController
   end
 
   def account_home_feed
-    Feed.new(:home, current_account)
+    HomeFeed.new(current_account)
   end
 
   def insert_pagination_headers