* Fix account tags not being saved correctly

Regression from f371b32

Fix Tag#discoverable not returning tags where listable is nil instead of true

Add notice when saving hashtags in admin UI

Change public hashtag and directory pages to return 404 for forbidden tags

* Remove unused locale string

* Add HTTP signature requirement for served ActivityPub resources

* Change `SECURE_MODE` to `AUTHORIZED_FETCH`

* Add 'Signature' to 'Vary' header and improve code style

* Improve code style by adding `public_fetch_mode?` method

* Nascent tag menu on frontend

* Hook up frontend to search

* Tag intersection backend first pass

* Update yarnlock

* WIP

* Fix for tags not searching correctly

* Make radio buttons function

* Simplify radio buttons with modeOption

* Better naming

* Rearrange options

* Add all/any/none functionality on backend

* Small PR cleanup

* Move to service from scope

* Small cleanup, add proper service tests

* Don't use send with user input :D

* Set appropriate column header

* Handle auto updating timeline

* Fix up toggle function

* Use tag value correctly

* A bit more correct to use 'self' rather than 'all' in status scope

* Fix some style issues

* Fix more code style issues

* Style select dropdown more better

* Only use to_id'ed value to ensure no SQL injection

* Revamp frontend to allow for multiple selects

* Update backend / col header to account for more flexible tagging

* Update brakeman ignore

* Codeclimate suggestions

* Fix presenter tag_url

* Implement initial PR feedback

* Handle additional tag streaming

* CodeClimate tweak

* Compensate for scrollbar disappearing when media modal visible

Make auth pages backgrounds lighter

* Fix typo

* Add RSS feed for accounts

* Add RSS feeds for hashtags

* Fix code style issues

* Fix code style issues

* Encode custom emojis as resolveable objects in ActivityPub

* Improve code style

- Objects must have attributedTo instead of actor
- The current attribute belongs to CollectionPage, not Collection

* Improve webfinger templates and make tests more flexible

* Clean up AS2 representation of actor

* Refactor outbox

* Create activities representation

* Add representations of followers/following collections, do not redirect /users/:username route if format is empty

* Remove unused translations

* ActivityPub endpoint for single statuses, add ActivityPub::TagManager for better
URL/URI generation

* Add ActivityPub::TagManager#to

* Represent all attachments as Document instead of Image/Video specifically
(Because for remote ones we may not know for sure)

Add mentions and hashtags representation to AP notes

* Add AP-resolvable hashtag URIs

* Use ActiveModelSerializers for ActivityPub

* Clean up unused translations

* Separate route for object and activity

* Adjust cc/to matrices

* Add to/cc to activities, ensure announce activity embeds target status and
not the wrapper status, add "id" to all collections

* Fix #2120 - Use Status#as_tag_timeline on public hashtag page

* Update tags_controller.rb

from accounts/tags because it's a terribly inefficient way to paginate
large sets of data