Add setting for whether to crop images in unexpanded toots (#12126)

app/controllers/settings/preferences_controller.rb

app/javascript/mastodon/components/media_gallery.js

app/javascript/mastodon/initial_state.js

app/lib/user_settings_decorator.rb

app/models/user.rb

app/serializers/initial_state_serializer.rb

app/views/settings/preferences/appearance/show.html.haml

config/locales/en.yml

config/locales/simple_form.en.yml

config/settings.yml