Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `config/webpack/configuration.js`:
  Upstream updated the `js-yaml` dependency, which changed how to call it.
  Those changes conflicted because that code is pretty different in glitch-soc
  which has to deal with its more complex theming system.
  Proceeded to the same compatibility changes in glitch-soc's code.
- `package.json` and `yarn.lock`:
  Not really a conflict, just glitch-soc-specific dependencies textually too
  close to some dependencies updated upstream.

app/views/media/player.html.haml

@@ -10,7 +10,7 @@
   = render partial: 'layouts/theme', object: @theme
 
 - if @media_attachment.video?
-  = react_component :video, src: @media_attachment.file.url(:original), preview: @media_attachment.thumbnail.present? ? @media_attachment.thumbnail.url : @media_attachment.file.url(:small), blurhash: @media_attachment.blurhash, width: 670, height: 380, editable: true, detailed: true, inline: true, alt: @media_attachment.description do
+  = react_component :video, src: @media_attachment.file.url(:original), preview: @media_attachment.thumbnail.present? ? @media_attachment.thumbnail.url : @media_attachment.file.url(:small), frameRate: @media_attachment.file.meta.dig('original', 'frame_rate'), blurhash: @media_attachment.blurhash, width: 670, height: 380, editable: true, detailed: true, inline: true, alt: @media_attachment.description, media: [ActiveModelSerializers::SerializableResource.new(@media_attachment, serializer: REST::MediaAttachmentSerializer)].as_json do
     %video{ controls: 'controls' }
       %source{ src: @media_attachment.file.url(:original) }
 - elsif @media_attachment.gifv?