* OEmbed support for PreviewCard
* Improve ProviderDiscovery code failure treatment
* Do not crawl links if there is a content warning, since those
don't display a link card anyway
* Reset db schema
* Fresh migrate
* Fix rubocop style issues
Fix#1681 - return existing access token when applicable instead of creating new
* Fix test
* Extract http client to helper
* Improve oembed controller
* Fix#2119 - Whenever about to send a HTTP request, normalize the URI
* Add test for IDN request in FetchLinkCardService
* Perform IDN normalization on domains before they are stored in the DB
fix ProcessFeedService pushing status into distribution if called a second time
while the first is still running (i.e. when a PuSH comes after a Salmon slap),
fix not running escape on spoiler text before emojify
Federate spoiler_text using warning attribute on <content /> instead of a <category term="spoiler" />
Clean up schema file from accidental development migrations
Yamagishi Kazutoshi