Dispatcher: Add getTotalOutboundCount()

This adds a method getTotalOutboundCount() to the Dispatcher class to
return the number of queued outbound packets.

Signed-off-by: Frieder Schrempf <frieder@fris.de>

Author: fschrempf

src/Dispatcher.h

@@ -167,6 +167,9 @@ class Dispatcher {
   Packet* obtainNewPacket();
   void releasePacket(Packet* packet);
   void sendPacket(Packet* packet, uint8_t priority, uint32_t delay_millis=0);
+  uint32_t getTotalOutboundCount() {
+    return _mgr->getOutboundCount(0xFFFFFFFF);
+  }
 
   unsigned long getTotalAirTime() const { return total_air_time; }  // in milliseconds
   unsigned long getReceiveAirTime() const {return rx_air_time; }