Archive old releases for performance / clarity

Localize.drupal.org was built with the idea in mind that it can just slurp in all the releases until it becomes a problem that old releases are disturbing. Now that is a problem. We have over 4x as many releases as projects and it is hard for translators to figure out which releases to translate strings for. Which are the supported branches of the project and what are the latest releases on those branches to translate for?

There are lots of old releases for many projects on the system that should be archived. Not deleted/removed. If we'd delete/remove them, we'd loose history. At least we should keep their exported .po files somewhere for posterity (loosing part of the history, ie. the per-string translation attribution and rejected suggestions for old strings). I think that is a reasonable compromise, however that should be ensured that all of the removed old releases have exported .po files for languages where translations are present.

Although this would be somewhat of a localize.drupal.org specific feature, it can be made settings in combination with the server and packager, so if packager has files for a release, we can remove its data (but not the exports).

Then time will come when we'll need to rethink the exports, but maybe we can buy some time only dealing with the database first.

Marking postponed on #1931154: Make stats work again on localize.drupal.org.