Validate SiteProfile address for Germany

[rafa-munoz]

Current behavior

At the moment anyone can save any German address with the format that they want. This fact can create inconsistencies:

• We don't send addresses properly formated to third parties (e.g.: Google Maps).
• Clients do not know how to store in a proper way addresses and get lost with address line numbers.

Expected behavior

In order to have better control of that, we need to check all fields before saving using the following schema: https://en.wikipedia.org/wiki/Address_(geography)#Germany

• The postal code always consists of five digits.
• Building number can be a combination of numbers and letters. E.g.: 16A. It´s also possible that it does not exist, but those are corner cases for Government buildings.
• There are a few places that have house numbers but no street names.

[rafa-munoz]

@jefmoura @glind please check if you agree with that