Add company logo upload feature in config (will show on receipts)

database/database.sql

@@ -40,6 +40,7 @@ INSERT INTO `ospos_app_config` (`key`, `value`) VALUES
 ('recv_invoice_format', '$CO'),
 ('sales_invoice_format', '$CO'),
 ('tax_included', '0'),
+('company_logo', ''),
 ('barcode_content', 'id'),
 ('barcode_type', 'id'),
 ('barcode_width', '250'),