[FEATURE] Expose release dates of current and latest releases in metrics

**Is your feature request related to a problem? Please describe.**

In my-use case I find that version-checker reports most images as behind out of date (expected for now..), which means I need to use some other data to help determine what order we go after upgrades.

**Describe the solution you'd like**

It would be great if the metrics could expose release dates for the current and latest version of the app. I could then diff this and create an ordering (based on how out of date the release is).

Semver alone can't really offer the same thing here, because it depends on the release strategy of the application in question, plus you can't just diff the 2 semver versions to get a count of releases in between.

I think i would favour date difference over number-of-releases-behind (when looking at current vs latest).

**Describe alternatives you've considered**

https://outdated.sh/ is interesting, but I think it's only a cli tool.

Thanks!

L’issue ne nomme aucun fichier, test ni point d’entrée. Commencez par localiser les métriques existantes pour les versions actuelle et la plus récente, ainsi que la manière dont les métadonnées de release sont obtenues ; le travail est terminé lorsque les métriques exposent les dates de release des deux versions afin que leur différence d’ancienneté puisse être utilisée pour ordonner les mises à niveau.

Rédigé par le modèle d'indexation à partir du texte de l'issue.