Track receiver duplicate batches in web and OLED

include/data_model.h

@@ -47,6 +47,9 @@ struct MeterData {
 struct SenderStatus {
   MeterData last_data;
   uint32_t last_update_ts_utc;
+  uint32_t rx_batches_total;
+  uint32_t rx_batches_duplicate;
+  uint32_t rx_last_duplicate_ts_utc;
   bool has_data;
 };