Add a retry mechanism for communicating with the Foojay back-end

[jbartok]

See this issue and related PR.

It would be good if communication failures with the Foojay back-end wouldn't immediately make the plugin's resolving fail. It would be good if the plugin would retry a couple of times before giving up. I'm thinking 2-3 retries with increasing delays, not too long though, the Gradle build might have other toolchain resolvers configured, at some point we need to hand things over to those.

[ben-manes]

Yeah, it’s frustrating that the metadata queries break the build when the APIs is down and auto-download is disabled. The resolver shouldn’t assume uptime guarantees that isn’t being provided.

[bamboo]

The issue is in the backlog of the relevant team and is prioritized by them.

---

[renaudberube]

I opened a PR (#207 ) to replace the URL.openConnection with built-in Java Http Client. I don`t mind adding a retry mechanism in the same PR or another one if you prefer, if #207 is accepted.