BURs: fix normalization of uppercase characters in scripts.

Only downcase tags in aliases, implications, and category change
commands. Don't downcase mass update commands. Mass updates are
potentially case sensitive (for example: `mass update source:imageboard -> source:Imageboard`).

app/logical/bulk_update_request_processor.rb

@@ -19,17 +19,17 @@ class BulkUpdateRequestProcessor
 
       case line
       when /\A(?:create alias|aliasing|alias) (\S+) -> (\S+)\z/i
-        [:create_alias, $1, $2]
+        [:create_alias, Tag.normalize_name($1), Tag.normalize_name($2)]
       when /\A(?:create implication|implicating|implicate|imply) (\S+) -> (\S+)\z/i
-        [:create_implication, $1, $2]
+        [:create_implication, Tag.normalize_name($1), Tag.normalize_name($2)]
       when /\A(?:remove alias|unaliasing|unalias) (\S+) -> (\S+)\z/i
-        [:remove_alias, $1, $2]
+        [:remove_alias, Tag.normalize_name($1), Tag.normalize_name($2)]
       when /\A(?:remove implication|unimplicating|unimplicate|unimply) (\S+) -> (\S+)\z/i
-        [:remove_implication, $1, $2]
+        [:remove_implication, Tag.normalize_name($1), Tag.normalize_name($2)]
       when /\A(?:mass update|updating|update|change) (.+?) -> (.*)\z/i
         [:mass_update, $1, $2]
       when /\Acategory (\S+) -> (#{Tag.categories.regexp})\z/i
-        [:change_category, $1, $2]
+        [:change_category, Tag.normalize_name($1), $2.downcase]
       else
         [:invalid_line, line]
       end

app/models/bulk_update_request.rb

@@ -8,7 +8,6 @@ class BulkUpdateRequest < ApplicationRecord
   belongs_to :forum_post, optional: true
   belongs_to :approver, optional: true, class_name: "User"
 
-  before_validation :normalize_text
   validates_presence_of :reason, on: :create
   validates_presence_of :script
   validates_presence_of :title, if: ->(rec) {rec.forum_topic_id.blank?}
@@ -117,10 +116,6 @@ class BulkUpdateRequest < ApplicationRecord
   extend SearchMethods
   include ApprovalMethods
 
-  def normalize_text
-    self.script = script.downcase
-  end
-
   def update_tags
     self.tags = processor.affected_tags
   end