feat(xo-server/rest-api): support setting name_label/name_description

docs/restapi.md

@@ -121,6 +121,20 @@ Content-Type: application/x-ndjson
 {"name_label":"Debian 10 Cloudinit self-service","power_state":"Halted","url":"/rest/v0/vms/5019156b-f40d-bc57-835b-4a259b177be1"}
 ```
 
+## Properties update
+
+> This feature is restricted to `name_label` and `name_description` at the moment.
+
+```bash
+curl \
+  -X PATCH \
+  -b authenticationToken=KQxQdm2vMiv7jBIK0hgkmgxKzemd8wSJ7ugFGKFkTbs \
+  -H 'Content-Type: application/json' \
+  -H 'Accept: application/json' \
+  -d '{ "name_label": "The new name", "name_description": "The new description" }' \
+  'https://xo.example.org/rest/v0/vms/770aa52a-fd42-8faf-f167-8c5c4a237cac'
+```
+
 ## VM and VDI destruction
 
 For a VM: