Port SCSS changes from 011b032300

* Do not retry processing ActivityPub jobs raising validation errors

Jobs yielding validation errors most probably won't ever be accepted,
so it makes sense not to clutter the queues with retries.

* Lower RecordInvalid error reporting to debug log level

* Remove trailing whitespace

* Change e-mail whitelist/blacklist to not be checked when invited

And only when creating an account, not when updating it later

Fix #10648

* Fix test

Fixes #10652

* When trying to block an already-blocked domain, provide a link to the block

* Fix styling for links in flash messages

* Allow blocks to be upgraded but not downgraded

Fixes #1027

* Add "view context" button to media modal when opened from gallery

* Add "view context" button to video modal

Allow closing the video modal by navigating back in the browser,
just like the media modal

* Make the "mark media as sensitive" button more obvious in web UI

* Use eye-slash icon instead of eye icon to mean "hide"

- 3 items per row instead of 2
- Use blurhash for previews
- Animate/hover-to-play GIFs and videos
- Open media modal instead of opening status
- Allow opening status instead with ctrl+click and open in new tab

* Check that an invite link is valid before bypassing approval mode

Fixes #10656

* Add tests

* Only consider valid invite links in registration controller

* fixup

Fixes #1021

Fixes #1015

changed default pinned count to 5 to preserve default behavior

moved max pin count into constant

Fixes detailed status column

Fix https://github.com/tootsuite/mastodon/pull/10621#issuecomment-487316619

* Add blurhash

* Use fallback color for spoiler when blurhash missing

* Federate the blurhash and accept it as long as it's at most 5x5

* Display unknown media attachments as blurhash placeholders

* Improve style of embed actions and spoiler button

* Change blurhash resolution from 3x3 to 4x4

* Improve dependency definitions

* Fix code style issues

They will be enabled if the input has focus