Maintenance: Add missing gem 'csv' to gemfile, and only load it when it's actuallly used.

Gemfile

@@ -116,6 +116,9 @@ gem 'diffy'
 # feature - excel output
 gem 'writeexcel', require: false
 
+# feature - csv import/export
+gem 'csv', require: false
+
 # feature - device logging
 gem 'browser'
 

Gemfile.lock

@@ -165,6 +165,7 @@ GEM
     crack (0.4.5)
       rexml
     crass (1.0.6)
+    csv (3.2.0)
     daemons (1.4.1)
     dalli (2.7.11)
     debug_inspector (1.1.0)
@@ -667,6 +668,7 @@ DEPENDENCIES
   coffeelint
   composite_primary_keys
   coveralls
+  csv
   daemons
   dalli
   delayed_job_active_record

app/models/concerns/can_csv_import.rb

@@ -1,7 +1,5 @@
 # Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
 
-require 'csv'
-
 module CanCsvImport
   extend ActiveSupport::Concern
 
@@ -59,6 +57,7 @@ returns
         raise Exceptions::UnprocessableEntity, "Unable to read file '#{data[:file]}': #{e.inspect}"
       end
 
+      require 'csv' # Only load it when it's really needed to save memory.
       header, *rows = ::CSV.parse(data[:string], **data[:parse_params])
 
       header&.each do |column|
@@ -296,6 +295,8 @@ returns
         end
         rows_to_add = []
       end
+
+      require 'csv' # Only load it when it's really needed to save memory.
       ::CSV.generate(**params) do |csv|
         csv << header
         rows.each do |row|

app/models/translation.rb

@@ -1,7 +1,5 @@
 # Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
 
-require 'csv'
-
 class Translation < ApplicationModel
   before_create :set_initial
   after_create  :cache_clear
@@ -407,6 +405,7 @@ Get source file at https://i18n.zammad.com/api/v1/translations_empty_translation
     params = {
       col_sep: ',',
     }
+    require 'csv' # Only load it when it's really needed to save memory.
     rows = ::CSV.parse(content, params)
     rows.shift # remove header