Use "Former" prefix for historic countries

[Marigold]

@pabloarosado had an idea to use "Former " prefix for historic countries, e.g. USSR -> Former USSR, Yugoslavia -> Former Yugoslavia. Hannah and others approved it.

Scope

• Add a column to the countries_regions table to indicate if this country is historic
• Rename those countries in countries_regions and make sure regions grouping doesn't change
• Make sure population dataset works correctly after this change as it is used outside this repository
• Rename them in the grapher DB tables (entities themselves and the harmonization tables)
• Check for countries that need renaming in harmonized ETL steps

In case this turns out to be trickier than expected, we might do it as part of larger countries_regions refactoring.

[larsyencken]

Since this would touch a lot of ETL datasets, it would really make it easier to have a simple sanity checker, at least something that compared the range of values in each column in the primary key.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Marigold]

Removing wontfix, I think this is still important. We're still using custom solutions such as this, but having a unified approach would be nice.

[larsyencken]

@pabloarosado Hey, marking this one as "prio 3 - nice to have" for now, since we have some other correctness issues we'd like to fix first. But if at some stage you wanted to champion this, we'd be happy to help out.

[pabloarosado]

Hi @Marigold now that we have the new regions dataset, where we have information about historical regions, I think we don't need to impose this suffix to historical regions. So, if you agree, feel free to close this issue.