* feat: Register push subscription

* feat: Notify when mentioned

* feat: Boost, favourite, reply, follow, follow request

* feat: Notification interaction

* feat: Handle change of public key

* feat: Unsubscribe if things go wrong

* feat: Do not send normal notifications if push is enabled

* feat: Focus client if open

* refactor: Move push logic to WebPushSubscription

* feat: Better title and body

* feat: Localize messages

* chore: Fix lint errors

* feat: Settings

* refactor: Lazy load

* fix: Check if push settings exist

* feat: Device-based preferences

* refactor: Simplify logic

* refactor: Pull request feedback

* refactor: Pull request feedback

* refactor: Create /api/web/push_subscriptions endpoint

* feat: Spec PushSubscriptionController

* refactor: WebPushSubscription => Web::PushSubscription

* feat: Spec Web::PushSubscription

* feat: Display first media attachment

* feat: Support direction

* fix: Stuff broken while rebasing

* refactor: Integration with session activations

* refactor: Cleanup

* refactor: Simplify implementation

* feat: Set VAPID keys via environment

* chore: Comments

* fix: Crash when no alerts

* fix: Set VAPID keys in testing environment

* fix: Follow link

* feat: Notification actions

* fix: Delete previous subscription

* chore: Temporary logs

* refactor: Move migration to a later date

* fix: Fetch the correct session activation and misc bugs

* refactor: Move migration to a later date

* fix: Remove follow request (no notifications)

* feat: Send administrator contact to push service

* feat: Set time-to-live

* fix: Do not show sensitive images

* fix: Reducer crash in error handling

* feat: Add badge

* chore: Fix lint error

* fix: Checkbox label overlap

* fix: Check for payload support

* fix: Rename action "type" (crash in latest Chrome)

* feat: Action to expand notification

* fix: Lint errors

* fix: Unescape notification body

* fix: Do not allow boosting if the status is hidden

* feat: Add VAPID keys to the production sample environment

* fix: Strip HTML tags from status

* refactor: Better error messages

* refactor: Handle browser not implementing the VAPID protocol (Samsung Internet)

* fix: Error when target_status is nil

* fix: Handle lack of image

* fix: Delete reference to invalid subscriptions

* feat: Better error handling

* fix: Unescape HTML characters after tags are striped

* refactor: Simpify code

* fix: Modify to work with #4091

* Sort strings alphabetically

* i18n: Updated Polish translation

it annoys me that it's not fully localized :P

* refactor: Use current_session in PushSubscriptionController

* fix: Rebase mistake

* fix: Set cacheName to mastodon

* refactor: Pull request feedback

* refactor: Remove logging statements

* chore(yarn): Fix conflicts with master

* chore(yarn): Copy latest from master

* chore(yarn): Readd offline-plugin

* refactor: Use save! and update!

* refactor: Send notifications async

* fix: Allow retry when push fails

* fix: Save track for failed pushes

* fix: Minify sw.js

* fix: Remove account_id from fabricator

Require stylesheets in common.js because stylesheets are shared by the
entry points.

This implementation is a bit smaller and still has the following benefits:

* No need of app/javascript/packs/custom.js
For custom stylesheet, it typically has only
"require('../styles/custom.scss')" and is redundant.

* No need to extract vendor stylesheet to another asset
Extracting vendor stylesheet could be forgotten by developers who do not
use custom stylesheet.

* Fix #2922 - Load stylesheet from "custom.css" entrypoint when present

This is pretty much the same way it worked as before, albeit with
having to create app/javascript/packs/custom.js with
require('../styles/custom.scss') (or whatever you want really), which
will be a blank slate for you to import whatever you want

* Remove old assets directory

* Extract font-awesome into common.css and always load it

* Add semi to ESLint rules

* Add padded-blocks to ESLint rules

* Add comma-dangle to ESLint rules

* add config/webpack and storyboard

* add streaming/

* yarn test:lint -- --fix

* Create common chunk rather than vendor chunk

vendor chunk is a set of modules provided by external vendors, but now we
can have a chunk as a set of modules shared by multiple entry points,
which could be more efficent than having vendor chunk.

* Start rails-ujs in common.js

This is used by /settings/two_factor_authentication.

* Allow SCSS variables to be overridden with
  `app/javascript/pack/variables*.scss`

* Allow these SCSS variables to be overriden:
  * `$base-shadow-color`
  * `$base-overlay-background`
  * `$base-border-color`
  * `$simple-background-color`
  * `$primary-text-color`
  * `$valid-value-color
  * `$error-value-color`

Fixes #2941