Show latest recommended version, not latest, for platform extensions

[holly-cummins]

At the moment we don't use the platform at all, just a loose list of extensions. That means we're showing lots of 3.0.0.Alpha even though that's not a recommended version. We should cross-reference back to the platforms to read the latest recommended and show that.

[maxandersen]

maybe having a recommend AND latest makese sense to show? each with their own (nn days/weeks/months ago) release "timestamp"?

[holly-cummins]

This is hard, since we view by extension, not by platform, and the registry gives us the latest. We could fix this on the registry side (quarkusio/registry.quarkus.io#151 covers this change), or once quarkusio/registry.quarkus.io#179 is done, we can get the platform contents of the preferred platform and cross-reference against the extensions.