Rehearse the bus upgrade on a copy of the last snapshot with a tool of the nats module, and run the docker tests only as integration tests (issue 1642, ADR 0480 clause 6)

modules/nats/module.json

@@ -44,7 +44,8 @@
     "nats_backlog",
     "nats_buckets",
     "nats_users",
-    "nats_user_can"
+    "nats_user_can",
+    "nats_rehearse"
   ],
   "guards": [
     8222
@@ -185,7 +186,10 @@
         "env": {
           "MESH_NATS_MONITOR": "http://127.0.0.1:8222",
           "MESH_NATS_CONTAINER": "mesh-broker-nats",
-          "MESH_NATS_USERS_FILE": "/etc/nats/accounts.conf"
+          "MESH_NATS_USERS_FILE": "/etc/nats/accounts.conf",
+          "MESH_NATS_SNAPSHOT": "${dir:snapshots}/bus.tar",
+          "MESH_NATS_PROGRAM_DIR": "/var/lib/nats-module/snapshot",
+          "MESH_NATS_ENTRYPOINT_DIR": "/var/lib/nats-module/entrypoint"
         }
       },
       {