fix auto approver on register and new policy (#2506)

* fix issue auto approve route on register bug

This commit fixes an issue where routes where not approved
on a node during registration. This cause the auto approval
to require the node to readvertise the routes.

Fixes #2497
Fixes #2485

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

* hsic: only set db policy if exist

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

* policy: calculate changed based on policy and filter

v1 is a bit simpler than v2, it does not pre calculate the auto approver map
and we cannot tell if it is changed.

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

---------

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

integration/control.go

@@ -4,6 +4,7 @@ import (
 	"net/netip"
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
+	policyv1 "github.com/juanfont/headscale/hscontrol/policy/v1"
 	"github.com/ory/dockertest/v3"
 )
 
@@ -24,4 +25,5 @@ type ControlServer interface {
 	ApproveRoutes(uint64, []netip.Prefix) (*v1.Node, error)
 	GetCert() []byte
 	GetHostname() string
+	SetPolicy(*policyv1.ACLPolicy) error
 }