Rework map session

This commit restructures the map session in to a struct
holding the state of what is needed during its lifetime.

For streaming sessions, the event loop is structured a
bit differently not hammering the clients with updates
but rather batching them over a short, configurable time
which should significantly improve cpu usage, and potentially
flakyness.

The use of Patch updates has been dialed back a little as
it does not look like its a 100% ready for prime time. Nodes
are now updated with full changes, except for a few things
like online status.

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

integration/tailscale.go

@@ -27,7 +27,7 @@ type TailscaleClient interface {
 	Down() error
 	IPs() ([]netip.Addr, error)
 	FQDN() (string, error)
-	Status() (*ipnstate.Status, error)
+	Status(...bool) (*ipnstate.Status, error)
 	Netmap() (*netmap.NetworkMap, error)
 	Netcheck() (*netcheck.Report, error)
 	WaitForNeedsLogin() error