Optimize uri normalization (#4212)

* Add dependency on idn-ruby to speed up URI normalization

* Use normalized_host instead of normalize.host when applicable

When we are only interested in the normalized host, calling normalized_host
avoids normalizing the other components of the URI as well as creating a
new object

app/services/fetch_remote_status_service.rb

@@ -24,7 +24,7 @@ class FetchRemoteStatusService < BaseService
     xml.encoding = 'utf-8'
 
     account = author_from_xml(xml.at_xpath('/xmlns:entry', xmlns: TagManager::XMLNS))
-    domain  = Addressable::URI.parse(url).normalize.host
+    domain  = Addressable::URI.parse(url).normalized_host
 
     return nil unless !account.nil? && confirmed_domain?(domain, account)
 
@@ -39,6 +39,6 @@ class FetchRemoteStatusService < BaseService
   end
 
   def confirmed_domain?(domain, account)
-    account.domain.nil? || domain.casecmp(account.domain).zero? || domain.casecmp(Addressable::URI.parse(account.remote_url).normalize.host).zero?
+    account.domain.nil? || domain.casecmp(account.domain).zero? || domain.casecmp(Addressable::URI.parse(account.remote_url).normalized_host).zero?
   end
 end