Fix #2744

* Change how CDN_HOST is passed down to make assets build reproducible

* Change webpacker/webpack configuration to dynamically load publicPath based on meta header

* Fix embedded layout missing the cdn-host meta header

* Move some inline styles to CSS files

* Move default_account_display_name span to fix useless tags with duplicate id

* Change handling of public pages spoiler text from inline CSS to dataset attribute

* Use the `dir` HTML attribute instead of inline CSS

* Move status action bar inline CSS to CSS file

* Hide logo resources from CSS file, not inline CSS

Fixes #11601

* Move translation prompt styling from inline CSS to CSS file

* Move “invited by” styling on registration form from inline to CSS file

* Use the progress tag to display poll results in JS fallback

* Fix poll results JS-less fallback when the user has voted for an option

* Change account public page “moved” notice to use img tags instead of inline CSS

* Move OTP hint inline CSS to SCSS file

* Hide JS-less fallback vote progressbars from accessibility tools

Co-authored-by: Eugen Rochko <eugen@zeonfederated.com>

Also:

- Fix Mastodon logo not showing up in status embeds
- Fix blurhash not being used in status embeds
- Fix blurhash not being used in admin UI
- Fix autoplay param not working correctly on status embeds

Regression from #8942

* Add support for selecting a theme

* Fix codeclimate issues

* Look up site default style if current user is not available due to e.g. not being logged in

* Remove outdated comment in common.js

* Address requested changes in themes PR

* Fix codeclimate issues

* Explicitly check current_account in application controller and only check theme availability if non-nil

* codeclimate

* explicit precedence with &&

* Fix code style in application_controller according to @nightpool's suggestion, use default style in embedded.html.haml

* codeclimate: indentation + return

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

* add haml_lint to Gemfile

* add .haml-lint.yml

* fix warnings of haml_lint

* Replace browserify with webpack

* Add react-intl-translations-manager

* Do not minify in development, add offline-plugin for ServiceWorker background cache updates

* Adjust tests and dependencies

* Fix production deployments

* Fix tests

* More optimizations

* Improve travis cache for npm stuff

* Re-run travis

* Add back support for custom.scss as before

* Remove offline-plugin and babili

* Fix issue with Immutable.List().unshift(...values) not working as expected

* Make travis load schema instead of running all migrations in sequence

* Fix missing React import in WarningContainer. Optimize rendering performance by using ImmutablePureComponent instead of
React.PureComponent. ImmutablePureComponent uses Immutable.is() to compare props. Replace dynamic callback bindings in
<UI />

* Add react definitions to places that use JSX

* Add Procfile.dev for running rails, webpack and streaming API at the same time

See <https://glitch.social/users/bea/updates/434>

* Add sprockets-rails to Gemfile

* Add sprockets-rails to Gemfile.lock

* Update show.html.haml

* Update index.html.haml

* Update admin.html.haml

* Update auth.html.haml

* Update embedded.html.haml

* Update public.html.haml