Cannot set is_residential on custom sales order addresses

[alotmore]

If a sales order uses the default addresses from the customer record, the is_residential status carries over. However, if you set a custom address on the sales order for either billing or shipping, the is_residential flag does not appear to be exposed and cannot be set.

[iloveitaly]

@alotmore which API version are you using?

Feel free to submit a PR for a fix!