Column picker in the Bill edit form

To the Bill edit form was added column picker.

It contains next columns:

• Description;
• Brand (displays if company setting is switched on);
• Category (displays if company setting is switched on);
• Qty Per Carton(Displays only if the vendor setting is switched on);
• Num. of Cartons(Displays only if the vendor setting is switched on);
• Carton Per Pallet(Displays only if the vendor setting is switched on);
• Num. of Pallets(Displays only if the vendor setting is switched on);
• Original Cost;
• Customer;
• Billable;
• PO#;
• Expenses;
• Task.