[SDKs] Clients should warn when they're expecting a newer API server
Sometimes it happens that our users have trouble because they're using client software that's written for an API server that's newer than what they're actually working on. #3783 is an example of this problem.
Our client software should detect this situation and at least warn about it. Each program should know the earliest API server it works with, and check that against the information exposed in the discovery document.