Allow to disable telemetry alarams (#4981)

* Allow to disable telemetry alarams

This mainly useful for cheap transceivers that have telemetry but no power amplifier and very limited range of often 10-20 meters. This includes fishpepper's tinyFISH FC (and its legal/illegal clones) and also Spektrum BNF models.

* Always disable a warning when RSSI Warnings are disabled

* Compile fix

* Fix typos, also mute sensor lost

Refactor the FrskyRSSIAlarm[2] into a EEPROM compatible RssiAlarm struct

* Compile fixes

* Also refactor Companion

* Cleanup unused datastruct on ARM

* Compile fix for AVR

* Change int to uin8_t for avr

* Fix strings

companion/src/eeprominterface.cpp

@@ -1392,8 +1392,6 @@ void FrSkyData::clear()
   mAhPersistent = 0;
   storedMah = 0;
   fasOffset = 0;
-  rssiAlarms[0].clear(2, 45);
-  rssiAlarms[1].clear(3, 42);
   for (int i=0; i<4; i++)
     screens[i].clear();
   varioSource = 2/*VARIO*/;
@@ -1560,6 +1558,7 @@ void ModelData::clear()
     timers[i].clear();
   swashRingData.clear();
   frsky.clear();
+  rssiAlarms.clear();
   for (int i=0; i<CPN_MAX_SENSORS; i++)
     sensorData[i].clear();