Add UDP multicast support on linux. (#6342)

* Add UDP multicast support on linux.

Closes #6326

We tested it an it works.

This is really hacky to say the least.

* Add libuv to Linux packaging

* Trunkadunk

* Correct ref

* Add libuv1-dev to setup-native

---------

Co-authored-by: vidplace7 <vidplace7@gmail.com>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/main.cpp

@@ -822,6 +822,11 @@ void setup()
 #ifdef HAS_UDP_MULTICAST
     LOG_DEBUG("Start multicast thread");
     udpThread = new UdpMulticastThread();
+#ifdef ARCH_PORTDUINO
+    // FIXME: portduino does not ever call onNetworkConnected so call it here because I don't know what happen if I call
+    // onNetworkConnected there
+    udpThread->start();
+#endif
 #endif
     service = new MeshService();
     service->init();