Adds serial commands to get stats

- Added formatStatsReply, formatRadioStatsReply, and formatPacketStatsReply methods in MyMesh for both simple_repeater, simple_room_server, and simple_sensor.
- Updated CommonCLI to handle new stats commands.

examples/simple_sensor/SensorMesh.h

@@ -20,6 +20,7 @@
 #include <helpers/AdvertDataHelpers.h>
 #include <helpers/TxtDataHelpers.h>
 #include <helpers/CommonCLI.h>
+#include <helpers/StatsFormatHelper.h>
 #include <helpers/ClientACL.h>
 #include <RTClib.h>
 #include <target.h>
@@ -69,6 +70,9 @@ public:
   void formatNeighborsReply(char *reply) override {
     strcpy(reply, "not supported");
   }
+  void formatStatsReply(char *reply) override;
+  void formatRadioStatsReply(char *reply) override;
+  void formatPacketStatsReply(char *reply) override;
   mesh::LocalIdentity& getSelfId() override { return self_id; }
   void saveIdentity(const mesh::LocalIdentity& new_id) override;
   void clearStats() override { }