Replace Paperclippable ContentConfig

The old Paperclip configuration was very clever and easy to use but it
was also a complicated implementation building on the complicated Spree
preference system.

I simplified this with Active Storage, storing simple references to blob
ids and default URLs as backup.

lib/open_food_network/paperclippable.rb

@@ -1,51 +0,0 @@
-# frozen_string_literal: true
-
-# Allow use of Paperclip's has_attached_file on non-ActiveRecord classes
-# https://gist.github.com/basgys/5712426
-
-module OpenFoodNetwork
-  module Paperclippable
-    def self.included(base)
-      base.extend(ActiveModel::Naming)
-      base.extend(ActiveModel::Callbacks)
-      base.include(ActiveModel::Validations)
-      base.include(Paperclip::Glue)
-
-      # Paperclip required callbacks
-      base.define_model_callbacks(:save, only: [:after])
-      base.define_model_callbacks(:commit, only: [:after])
-      base.define_model_callbacks(:destroy, only: [:before, :after])
-
-      # Initialise an ID
-      base.__send__(:attr_accessor, :id)
-      base.instance_variable_set :@id, 1
-    end
-
-    # ActiveModel requirements
-    def to_model
-      self
-    end
-
-    def valid?()      true end
-
-    def new_record?() true end
-
-    def destroyed?()  true end
-
-    def save
-      run_callbacks :save do
-      end
-      true
-    end
-
-    def errors
-      obj = Object.new
-      def obj.[](_key) [] end
-
-      def obj.full_messages() [] end
-
-      def obj.any?() false end
-      obj
-    end
-  end
-end