* Make host_meta/webfinger replies cacheable (fixes #6100)

Drop common code for handling users and sessions as webfinger queries
are very basic, public APIs.

Also explicitly mark results as cacheable with “expires_in”.

* Add “Vary: Accept” header for caching since content-negociation is used

Getting Started column obtained many links, and it became much taller.
Because of its height, Getting Started column required long scrolling on
devices with small screen, such as 4 inch phones and 10 inch laptops.

This change moves the mastodon which took large space on the column to
drawer column. The drawer column has only the compose form and has more
space.

* removed references to hideOnMobile in column_link and getting_started

* add mute, block, conversationMute actions to detailed status dropdown (fixes #1226)

* remove unused withDismiss in detailed status

* Add aria-autocomplete='list' in Textaria

ref: https://www.w3.org/TR/wai-aria-1.1/#aria-autocomplete

* Make detect empty string brefore assign upload description

* Change code elements in keyboard-shortcuts component to kbd

* Add validation for onMuteNotifications

* Reduce motion for boost animation

Fixes #5833

* Fix ternary expression

* Remove onSave method in mapped properties for column_settings

* Make web_push_subscription.register an action

* removed references to hideOnMobile in column_link and getting_started

* move keyboard shortcuts back below blocked users

Deleted users are technically suspended, but the code displaying their status
in the admin interface was broken and displayed a javascript object holding
translations of the possible user roles instead.

Specifically, this commit:

- changes S::TFA::{Confirmations,RecoveryCodes}Controller to derive from
  S::BaseController, because this gives us the necessary actions and
  packs
- prepends set_pack to Auth::SessionsController's action chain so that
  it takes effect in time for render :two_factor

* Add aria-autocomplete='list' in Textaria

ref: https://www.w3.org/TR/wai-aria-1.1/#aria-autocomplete

* Make detect empty string brefore assign upload description

* Change code elements in keyboard-shortcuts component to kbd

* Update Korean translation

* Translate Korean for javascript

* Add missing translations on simple_form

* Add Slovak translation

* Slovak translation: i18n-normalize

* i18n: (zh-CN) Change `工作人员` (staff) to `管理人员`
Suggested by @Gargron at https://github.com/tootsuite/mastodon/pull/6005#discussion_r156678109

* i18n: (zh-CN) Change `协管` to `监察员`

* i18n: (zh-CN) Fix all "Are you" questions

* i18n: (zh-CN) Various improvements

* i18n: (zh-CN) Final clean-up

* i18n: (zh-CN) Change translation for 500

* i18n: (zh-CN) Remove spaces between time distances

* i18n: (zh-CN) Improve translations

* Last minute Dutch strinfupdate

* Last minute Dutch strings update

* Fixing Weblate output errors

* Fixing Weblate output errors

* Fixing more Weblate rubish

Weblate is also changing some " to ' - I think that is not a problem

* Fixing more weblate stuff

* Fixing

* Update nl.yml

This commit also:

- exposes the local-only emoji so that it can be used in examples
- allows local_only to be set explicitly, i.e. for timeline filtering
  specs