And rewrite cloud detection to try to do only zero or one metadata
discovery request for all clouds, only doing a first (or second) as
confidence increases. Work remains for Windows, but a start.
And add Cloud to tailcfg.Hostinfo, which helped with testing using
"tailcfg debug hostinfo".
Updates #4983 (Linux only)
Updates #4984
Change-Id: Ib03337089122ce0cb38c34f724ba4b4812bc614e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Brad Fitzpatrick
Maisem Ali