Hostinfo.WireIngress is used as a hint that the node intends to use
funnel. We now send another field, IngressEnabled, in cases where
funnel is explicitly enabled, and the logic control-side has
been changed to look at IngressEnabled as well as WireIngress in all
cases where previously the hint was used - so we can now stop sending
WireIngress when IngressEnabled is true to save some bandwidth.
Updates tailscale/tailscale#11572
Updates tailscale/corp#25931
Signed-off-by: Irbe Krumina <irbe@tailscale.com>