RMA SO wizard quantity default to 0 and show max

[jbaudoux]

When creating an RMA from an SO, it currently opens a wizard with all lines of the SO with the quantity preset to the SO delivered quantity (in fact returnable delivered quantity).

I have several customers that are managing large SOs and facing an RMA for one or few lines. This requires to delete all extra lines or set the quantity to 0 which is cumbersome. In this case, what would be convenient is to have the quantity by default to 0 and have another column showing the max quantity that can be returned.

I can understand this change of approach may not be convenient to current users. Should this change be implemented in another module like rma_sale_show_max_qty or should this be a configuration option in the base rma_sale module?