types/netmap: remove some old TODOs

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

types/netmap/netmap.go

@@ -57,11 +57,8 @@ type NetworkMap struct {
 
 	User   tailcfg.UserID
 	Domain string
-	// TODO(crawshaw): reduce UserProfiles to []tailcfg.UserProfile?
+
-	// There are lots of ways to slice this data, leave it up to users.
 	UserProfiles map[tailcfg.UserID]tailcfg.UserProfile
-	// TODO(crawshaw): Groups       []tailcfg.Group
-	// TODO(crawshaw): Capabilities []tailcfg.Capability
 }
 
 // MagicDNSSuffix returns the domain's MagicDNS suffix (even if