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/models/custom_emoji.rb

@@ -3,7 +3,7 @@
 #
 # Table name: custom_emojis
 #
-#  id                 :bigint           not null, primary key
+#  id                 :integer          not null, primary key
 #  shortcode          :string           default(""), not null
 #  domain             :string
 #  image_file_name    :string