Punycode URI normalization (#2370)

* 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

app/models/domain_block.rb

@@ -13,4 +13,12 @@ class DomainBlock < ApplicationRecord
   def self.blocked?(domain)
     where(domain: domain, severity: :suspend).exists?
   end
+
+  before_validation :normalize_domain
+
+  private
+
+  def normalize_domain
+    self.domain = TagManager.instance.normalize_domain(domain)
+  end
 end