Add proto rpc interface for cli

This commit adds proto rpc definitions for the communication needed for
the CLI interface.
This will allow us to move the rest of the CLI interface over to gRPC
and in the future allow remote access

proto/headscale/v1/routes.proto

@@ -0,0 +1,25 @@
+syntax = "proto3";
+package headscale.v1;
+option  go_package = "github.com/juanfont/headscale/gen/go/v1";
+
+message Routes {
+    repeated string advertised_routes = 1;
+    repeated string enabled_routes    = 2;
+}
+
+message GetMachineRouteRequest {
+    uint64 machine_id = 1;
+}
+
+message GetMachineRouteResponse {
+    Routes routes = 1;
+}
+
+message EnableMachineRoutesRequest {
+    uint64          machine_id = 1;
+    repeated string routes     = 2;
+}
+
+message EnableMachineRoutesResponse {
+    Routes routes = 1;
+}