Port 5bf100f87b to glitch-soc

This is only available if the instance-wide setting isn't set and allows
people to hide their own followers count. This does not hide others' to
them.

Fixes #6060

Port 2e1b5edfea to glitch-soc

Port 4f42238c29 to glitch-soc

Port 90b64c0069 to glitch-soc

This is both for consistency with account timelines and to not mess with
the logic used to decide whether going back in the browser's history is
going to make us leave the WebUI.

Port 8182b61518 to glitch-soc

Port 4eeda67727 to glitch-soc

Port 06252ec71e to glitch-soc

Port 5ea643b279 to glitch-soc

Port 46061dc041 to glitch-soc

Port 7403e5d306 to glitch-soc

Port 12ab15e584 to glitch-soc

Port 13dce12665 to glitch-soc

Port SCSS changes from 087e118971 to glitch flavour

It should not be necessary thanks to our Content Security Policy, but best
be sure in case a server's CSP is incorrect. Also, avoids a CSP warning about
loading remote scripts.

* Make sure loading indicator has enough vertical space
* Respect reduce_motion setting for loading indicator

Port 4ede51743e to glitch-soc

* Add failing test for windows-1251 link cards

* Ignore low-confidence CharlockHolmes guesses

Fixes #9466

* Fix no method error when charlock holmes cannot detect charset

* Make sure loading indicator has enough vertical space

* Respect reduce_motion setting for loading indicator

Fixes #855

* Move #set_user to Admin::BaseController

* Rename Admin::TwoFactorAuthenticationsController

from `#set_user` to `#set_target_user` .

* Prepare to load onboarding as a full page

* Update the first-time introduction

* Improve responsive design

* Replace speech bubble with logo

* Increase text size and reword first paragraph

* Remove "most popular" tab from profile directory, add responsive design

* Remove unused translations

Add timeout of 10s to web push requests

There is no reason to disable the composer textarea when some media metadata
is being modified, nor is there any reason to focus the textarea when some
media metadata has been modified (prevents clicking one image's description
field right after having modified another).

Port c58c00651b to glitch-soc

Port part of 7c48688d85 to glitch-soc

* create FilterBar componer and its container, unstyled

* introduce basic styling for FilterBar

* add selection css

* allow FilterBar to display active CSS with js

* connect the FilterBar to the Redux state

* change getNotifications to use filter

* remove temporary comments

* add an option to turn the FilterBar off in settings

* fix showFilterBar data type to boolean

* fix eslint errors

* add English and Polish translations

* allowed filter bar overflow to accomodate for longer languages

* fix mispelled translation key

* add unified CSS look

* replace text in FilterBar with icons

* add tooltips

* replace text @ with an icon

* introduce simple and advanced filtering view

* add ability to toggle the advanced view

* add Polish translations

* change Advanced View description to be more clear

* make each filter flush notifications and load new ones, fixing pagination

* simplify getNotifications once frontend filtering is not needed for FilterBar

* add a semicolon

* Revert "simplify getNotifications once frontend filtering is not needed for FilterBar"

This reverts commit 9f4be78571.

* reset filter to 'all' when turning off FilterBar

Fixes #7112

* Do not animate account header art if user's GIF autoplay setting is off

Fixes #9472

* Honour currently logged-in user's GIF autoplay setting for account avatars

Fixes #9467

* Fix avatar display on some public pages when data is stored on a different host

* Use ternary operator instead of if/else for avatar/header URL

* Error message for avatar image that's too large. #9204

* Code climate/formatting

* Removed avatar error message

* Moved valid image dimentions check to update service

* removed unnescessary begin block

* code climate formatting

* code climate indent fix