Problem

I would like to consolidate Order lines for the same Item into a single Picking line.

Solutions

It cannot be done

You can cannot combine Order lines per Item.

The warehouse shipment lines have a one to one relationship with the order lines and you can only ship from one bin at a time per line. 

Mobile WMS 

Does not add any functionality regarding Pick creation. 

Seek professional assistance

You need to have this conversation with a dedicated Warehouse consultant, most likely via your ERP-Partner.