add default quantity on a product bundle
Product bundles can define a minimum and a maximum. The minimum is implicitly defining the default value. This is a serious limitation for users that want to set a default value which is not the minimum.
Simple example: you want your minimum to be 0 or 1 but the default to be 2.
For a 0 minimum, one can use the optional flag but that has impact on the user experience (and the layout).
