Bug 7178: Follow-up Improve order item creation

Bug 7178: Follow-up Improve order item creation

Move SQL code from Perl script to Perl module
Replace SHOW COLUMNS by $dbh->column_info()
Update total on neworderempty.pl when adding or deleting items

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Tested ok for ordering and receiving items.
Total updated correctly.

Note: There are lots of errors in the logs before and after applying
the patch. A follow up is needed.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>