Extract by_domain_length scope in DomainNormalizable concern (#29517)

app/models/concerns/domain_normalizable.rb

@@ -5,6 +5,18 @@ module DomainNormalizable
 
   included do
     before_validation :normalize_domain
+
+    scope :by_domain_length, -> { order(domain_char_length.desc) }
+  end
+
+  class_methods do
+    def domain_char_length
+      Arel.sql(
+        <<~SQL.squish
+          CHAR_LENGTH(domain)
+        SQL
+      )
+    end
   end
 
   private