improve receipt/details reports and implement number formatting

1) eager load reports for receipt/details
2) introduce number_format lookups to replace print_settings for number formatting
3) implement NumberFormattable concern, reference number_format lookups or print_settings if not exist, to get number format settings and number formatting
4) replace rails NumberHelper.number_with_precision with NumberFormattable.number_format hopefully to reduce overhead, formatting numbers for huge lists of data

app/pdf/sale_items_pdf.rb

@@ -1,5 +1,5 @@
 class SaleItemsPdf < Prawn::Document
-  include ActionView::Helpers::NumberHelper
+  include NumberFormattable
   attr_accessor :label_width,:price_column_width,:page_width, :page_height, :margin, :price_width, :item_width, :header_font_size, :item_font_size,:item_height,:qty_width,:total_width,:item_description_width,:text_width
 
   def initialize(printer_settings, shop_details, period, type, account, from_date, to_date, shift, sale_items, total_other_charges)
@@ -41,17 +41,6 @@ class SaleItemsPdf < Prawn::Document
     # font "public/fonts/Zawgyi-One.ttf"
     # font "public/fonts/padauk.ttf"
 
-    #precision checked
-    if printer_settings.precision.to_i > 2
-        printer_settings.precision = 2
-    end
-    #check delimiter
-    if printer_settings.delimiter
-        delimiter = ","
-    else
-        delimiter = ""
-    end
-
     header( shop_details)
 
     stroke_horizontal_rule