control/controlclient: plumb health.Tracker

Updates #11874
Updates #4136

Change-Id: Ia941153bd83523f0c8b56852010f5231d774d91a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f