Feature Request: Individual post highlights should show views by country

### Impacted plugin

Jetpack

### What

I would like to see a geographic breakdown of views for a single post

### How

### Goal
When viewing the stats for a single post I can see views, likes, comments, and a breakdown by day. When viewing the stats for a single post's email open rates, I can see geographic information of people who are viewing the email. I would like to see those same geographic stats for web traffic.

### Details
When viewing the stats for a single post at a URL like the one below I am unable to see geographic information about how well the post is doing in a particular county. This is important as some of our posts are written to target a specific audience in a specific part of the world. Being able to tell if our posts are reaching folks by country would help us ascertain the reach of our posts and the success of our writing.

https://wordpress.com/stats/post/12345/mysite.com

### Notes

This data is available for email opens at a URL like the one below. This information is useful, but is incomplete when used in conjunction with the web stats. I can tell if folks subscribed to my site via jetpack email subscriptions are reading (or at least opening!) individual emails, but not if they are visiting the site directly.

### Screenshots
Country stats for email opens for a single post:

The request concerns the single-post stats view at the WordPress.com URL in the issue and compares it with geographic data for email opens. Start by locating the implementation of that stats view and its existing country-data source. Done would mean showing a country breakdown for web views of an individual post, with coverage comparable to the requested email-open geography.

Written by the indexing model from the issue text.