feat/xr_device_driver_service_tool

Support creating XR services directly from test tool. This allows demonstrations without multi-layer setup with emulated routers.

src/device/service/drivers/xr/README_XR.md

@@ -146,6 +146,18 @@ arbitrary endpoints in the topology (with consequent underlying XR service insta
     PYTHONPATH=../../../../ ./service-cli.py list
     PYTHONPATH=../../../../ ./service-cli.py delete 43a8046a-5dec-463d-82f7-7cc3442dbf4f
 ```
+
+It is also possible to create direct XR services without multi-layer services. E.g.:
+```
+    PYTHONPATH=../../../../  ./service-cli.py create-xr FooService X1-XR-CONSTELLATION  "XR HUB 1|XR-T1" "XR LEAF 2|XR-T1"
+```
+
+Additionally it is possible to list services and endpoints:
+```
+    PYTHONPATH=../../../../  ./service-cli.py list-endpoints
+    PYTHONPATH=../../../../  ./service-cli.py delete 43a8046a-5dec-463d-82f7-7cc3442dbf4f
+```
+
 The PYTHONPATH is mandatory. Suitable topology JSON must have been loaded before. With the
 CocroachDB persistence, it is sufficient to load the topology once and it will persist.