Activating TX Low Pass Filter in Second IF IC (#1470)

* Activating TX Low Pass Filter in Second IF IC
* solving PR conversation revisions
* Final TX LPF decision for ADSB_TX
* Small comments correction.
* Added set TX LPF also  in APRS, BurgerPgr,Jammer

firmware/application/apps/ui_rds.cpp

@@ -187,6 +187,7 @@ void RDSView::start_tx() {
     else
         frame_datetime.clear();
 
+    transmitter_model.set_baseband_bandwidth(1'750'000);  // Big Spectrum harmonics reduction, and now quicker decoding time.
     transmitter_model.enable();
 
     tx_thread = std::make_unique<RDSThread>(frames);