Redo DNS configuration (#2034)

this commit changes and streamlines the dns_config into a new
key, dns. It removes a combination of outdates and incompatible
configuration options that made it easy to confuse what headscale
could and could not do, or what to expect from ones configuration.

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

hscontrol/mapper/tail.go

@@ -36,8 +36,7 @@ func tailNodes(
 	return tNodes, nil
 }
 
-// tailNode converts a Node into a Tailscale Node. includeRoutes is false for shared nodes
-// as per the expected behaviour in the official SaaS.
+// tailNode converts a Node into a Tailscale Node.
 func tailNode(
 	node *types.Node,
 	capVer tailcfg.CapabilityVersion,

hscontrol/mapper/tail_test.go

@@ -55,12 +55,14 @@ func TestTailNode(t *testing.T) {
 		{
 			name: "empty-node",
 			node: &types.Node{
-				Hostinfo: &tailcfg.Hostinfo{},
+				GivenName: "empty",
+				Hostinfo:  &tailcfg.Hostinfo{},
 			},
 			pol:        &policy.ACLPolicy{},
 			dnsConfig:  &tailcfg.DNSConfig{},
 			baseDomain: "",
 			want: &tailcfg.Node{
+				Name:              "empty",
 				StableID:          "0",
 				Addresses:         []netip.Prefix{},
 				AllowedIPs:        []netip.Prefix{},