[ADD] product_customer_code_picking module v.7.0

Moving the MP: https://code.launchpad.net/~agilebg/stock-logistic-flows/adding_product_customer_code_picking/+merge/202472
Hi,

This section of code seems a little restrictive.  Consider a 2 level deep partner.  It would only take the direct parent.  I could be wrong but it feels like what you might want here is a list of ids and use a ('partner_id', in, partner_ids) in your search.

Just a general comment, maybe there is a good reason for ignoring the current partner and any higher up partners.