* 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

All the migrations have been updated to use BIGINTs for ID fields in the DB, but ActiveRecord needs to be told to treat those values as BIGINT as well. This PR does that.

* Add foreign key constraint to column `account` in `account_moderation_notes`

* Change account_id and target_account_id to non-nullable in account_moderation_notes

* Add dependent: :destroy to account and target_account in account_moderation_notes

* Add moderation note

* Add frozen_string_literal

* Make rspec pass