Add sampling by country options to QuickSurvey.
An example survey will be necessary for us to build and test this survey.
* Sometimes we only need data from a specific country or region and sampling from all requests to get enough number of responses from the region is not an option (we will be asking a lot of users to provide data that we won't use.)
**What's already there?**
Client-side country information is available under window.Geo.country
= Acceptance criteria
 A survey can be configured to target an editor in a certain country
= Sign off steps
We want to avoid the problem where when this survey goes live there is a problem with the implementation. We will want to sign this off with research carefully to avoid this happening.