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

radio/src/opentx.cpp

@@ -1036,6 +1036,13 @@ void checkFailsafe()
 #else
 #define checkFailsafe()
 #endif
+#if defined(CPUARM)
+void checkRSSIAlaramsDisabled()
+{
+  if (g_model.rssiAlarms.disabled)
+    ALERT(STR_RSSIALARM_WARN, STR_NO_RSSIALARM, AU_ERROR);
+}
+#endif
 
 #if defined(GUI)
 void checkAll()
@@ -1053,6 +1060,9 @@ void checkAll()
   checkSwitches();
   checkFailsafe();
 #endif
+#if defined(CPUARM)
+  checkRSSIAlaramsDisabled();
+#endif
 
 #if defined(SDCARD) && defined(CPUARM)
   checkSDVersion();