feat: Deadzone option for NV14 sticks (#1777)

Imported from open-flysky/Flysky-OpenTX-Test-Branch

* companion: Don't nuke `stickDeadZone` setting

* Implement data storage properly

* Add missing check for NV14 storage struct sizes

* Formatting

* Use one less byte in the packed data struct
Thanks @raphaelcoeffic :)

* Move setting of stickDeadZone default

* Use a Choice combo rather than NumberEdit

* Good riddance magic number

* Also set default stick zone if setting is missing

* Teach tests about `STICK_DEAD_ZONE`

* Tweak choice width

* Cpn NV14 add stick dead zone to hardware and section labels

* Cpn NV14 align default pot names to radio

Co-authored-by: elecpower <neilh713@tpg.com.au>

radio/src/storage/storage_common.cpp

@@ -98,6 +98,11 @@ void postRadioSettingsLoad()
     g_eeGeneral.internalModule = DEFAULT_INTERNAL_MODULE;
   }
 #endif
+#if defined(STICK_DEAD_ZONE)
+  if (!g_eeGeneral.stickDeadZone) {
+    g_eeGeneral.stickDeadZone = DEFAULT_STICK_DEADZONE;
+  }
+#endif
 }
 
 #if defined(EXTERNAL_ANTENNA) && defined(INTERNAL_MODULE_PXX1)