Add new ROUTER_LATE role (#5528)

Will always rebroadcast packets, but will do so after all other modes.
Intended for router nodes that are there to provide additional coverage
in areas not already covered by other routers, or to bridge around
problematic terrain, but should not be given priority over other routers
in order to avoid unnecessaraily consuming hops.

By default, this role will rebroadcast during the normal client window.
However, if another node is overheard rebroadcasting the packet, then it
will be moved to a second window *after* the normal client one, with the
same timing behaviour.

src/mesh/FloodingRouter.cpp

@@ -24,11 +24,15 @@ bool FloodingRouter::shouldFilterReceived(const meshtastic_MeshPacket *p)
         printPacket("Ignore dupe incoming msg", p);
         rxDupe++;
         if (config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER &&
-            config.device.role != meshtastic_Config_DeviceConfig_Role_REPEATER) {
+            config.device.role != meshtastic_Config_DeviceConfig_Role_REPEATER &&
+            config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER_LATE) {
             // cancel rebroadcast of this message *if* there was already one, unless we're a router/repeater!
             if (Router::cancelSending(p->from, p->id))
                 txRelayCanceled++;
         }
+        if (config.device.role == meshtastic_Config_DeviceConfig_Role_ROUTER_LATE && iface) {
+            iface->clampToLateRebroadcastWindow(getFrom(p), p->id);
+        }
 
         /* If the original transmitter is doing retransmissions (hopStart equals hopLimit) for a reliable transmission, e.g., when
         the ACK got lost, we will handle the packet again to make sure it gets an ACK to its packet. */