DEV: enable frozen string literal on all files

This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.

Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging

script/import_scripts/phpbb3/database/database.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'mysql2'
 
 module ImportScripts::PhpBB3

script/import_scripts/phpbb3/database/database_3_0.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'database_base'
 require_relative '../support/constants'
 

script/import_scripts/phpbb3/database/database_3_1.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'database_3_0'
 require_relative '../support/constants'
 

script/import_scripts/phpbb3/database/database_base.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class DatabaseBase
     # @param database_client [Mysql2::Client]

script/import_scripts/phpbb3/importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../base'
 require_relative 'support/settings'
 require_relative 'database/database'

script/import_scripts/phpbb3/importers/attachment_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class AttachmentImporter
     # @param database [ImportScripts::PhpBB3::Database_3_0 | ImportScripts::PhpBB3::Database_3_1]

script/import_scripts/phpbb3/importers/avatar_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class AvatarImporter
     # @param uploader [ImportScripts::Uploader]

script/import_scripts/phpbb3/importers/bookmark_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class BookmarkImporter
     def map_bookmark(row)

script/import_scripts/phpbb3/importers/category_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class CategoryImporter
     # @param lookup [ImportScripts::LookupContainer]

script/import_scripts/phpbb3/importers/importer_factory.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'attachment_importer'
 require_relative 'avatar_importer'
 require_relative 'bookmark_importer'

script/import_scripts/phpbb3/importers/message_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class MessageImporter
     # @param database [ImportScripts::PhpBB3::Database_3_0 | ImportScripts::PhpBB3::Database_3_1]

script/import_scripts/phpbb3/importers/permalink_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class PermalinkImporter
     CATEGORY_LINK_NORMALIZATION = '/(viewforum.php\?)(?:.*&)?(f=\d+).*/\1\2'

script/import_scripts/phpbb3/importers/poll_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class PollImporter
     # @param lookup [ImportScripts::LookupContainer]

script/import_scripts/phpbb3/importers/post_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class PostImporter
     # @param lookup [ImportScripts::LookupContainer]

script/import_scripts/phpbb3/importers/user_importer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../support/constants'
 
 module ImportScripts::PhpBB3

script/import_scripts/phpbb3/support/constants.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class Constants
     ACTIVE_USER = 0

script/import_scripts/phpbb3/support/settings.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'yaml'
 
 module ImportScripts::PhpBB3

script/import_scripts/phpbb3/support/smiley_processor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class SmileyProcessor
     # @param uploader [ImportScripts::Uploader]

script/import_scripts/phpbb3/support/text_processor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ImportScripts::PhpBB3
   class TextProcessor
     # @param lookup [ImportScripts::LookupContainer]