feat(server/portforward): change route from /v1/openvpn/portforwarded to /v1/portforward

- This route has nothing to do with openvpn specifically
- Remove the `ed` in `portforwarded` to accomodate future routes such as changing the state of port forwarding
- maintaining retrocompatibility with `/v1/openvpn/portforwarded`
- maintaining retrocompatibility with `/openvpn/portforwarded`
- Moved to its own handler `/v1/portforward` instead of `/v1/vpn/portforward` to reduce the complexity of the vpn handler

internal/server/middlewares/auth/settings.go

@@ -35,6 +35,7 @@ func (s *Settings) SetDefaults() {
 			http.MethodGet + " /v1/updater/status",
 			http.MethodPut + " /v1/updater/status",
 			http.MethodGet + " /v1/publicip/ip",
+			http.MethodGet + " /v1/portforward",
 		},
 	}})
 }
@@ -131,4 +132,5 @@ var validRoutes = map[string]struct{}{ //nolint:gochecknoglobals
 	http.MethodGet + " /v1/updater/status":        {},
 	http.MethodPut + " /v1/updater/status":        {},
 	http.MethodGet + " /v1/publicip/ip":           {},
+	http.MethodGet + " /v1/portforward":           {},
 }