* Fix Sidekiq warnings about JSON serialization

This occurs on every symbol argument we pass, and every symbol key in hashes,
because Sidekiq expects strings instead.

See https://github.com/mperham/sidekiq/pull/5071

We do not need to change how workers parse their arguments because this has
not changed and we were already converting to symbols adequately or using
`with_indifferent_access`.

* Set Sidekiq to raise on unsafe arguments in test mode

In order to more easily catch issues that would produce warnings in production
code.

* Add support for editing for published statuses

* Fix references to stripped-out code

* Various fixes and improvements

* Further fixes and improvements

* Fix updates being potentially sent to unauthorized recipients

* Various fixes and improvements

* Fix wrong words in test

* Fix notifying accounts that were tagged but were not in the audience

* Fix mistake

* Add bell button

Fix #4890

* Remove duplicate type from post-deployment migration

* Fix legacy class type mappings

* Improve query performance with better index

* Fix validation

* Remove redundant index from notifications

* 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

* Spec for feed insert worker when missing records

* more specs!

* Refactor feed insert worker