Make 'registered office address' a structured field, so we can format it appropriately

[chrismear]

The 'registered office address' field for co-ops is currently just a string, which we present in forms using a textarea. Sometimes we need to display this address formatted into one line using commas, and other times we need to display it in block form with line breaks. This is difficult to do when the data is just a single string that the user may have entered in an unpredictable format.

Instead, we should capture the address as separate components (Address line 1, address line 2, city, region, country) so that we can format it how we please.