experiments: add wait flag to network simulators as well

Useful for running ns-3 only simulations.

experiments/simbricks/orchestration/simulators.py

@@ -195,6 +195,7 @@ class NetSim(Simulator):
         self.hosts_direct: list[HostSim] = []
         self.net_listen: list[NetSim] = []
         self.net_connect: list[NetSim] = []
+        self.wait = False
 
     def full_name(self) -> str:
         return 'net.' + self.name
@@ -229,6 +230,9 @@ class NetSim(Simulator):
     def sockets_wait(self, env: ExpEnv) -> tp.List[str]:
         return [s for (_, s) in self.listen_sockets(env)]
 
+    def wait_terminate(self) -> Bool:
+        return self.wait
+
 
 # FIXME: Class hierarchy is broken here as an ugly hack
 class MemDevSim(NICSim):