feat(radio,cpn): Updates for new joystick system (#3400)

* Reduce RAM usage for advanced joystick system on radio:
- Don't allocate memory blocks unless joystick mode is being used.
Support multiple radio joystick configurations in Companion:
- Save configured joystick settings by joystick name in Companion settings.
- Save last joystick name used in each profile.
- Reload joystick settings by name when profile is changed.

* Only show configuration for used axes and buttons in Companion.
Send actual number of configured joystick buttons from radio in USB packet.

* Fix issue where USB joystick not recognised if no buttons configured.

* Fix compiler warnings.

* Remove debugging.

* Fix crash in Companion.

* Change channel 8 to type 'dial', workaround for Linux mapping issue.

---------

Co-authored-by: Phil Mitchell <phil.a.mitchell@gmail.com>

radio/src/datastructs_private.h

@@ -638,6 +638,12 @@ PACK(struct USBJoystickChData {
 
 #if defined(USBJ_EX)
   NOBACKUP(
+    uint8_t btnCount() {
+      // Use one less joystick button for 2POS and 3POS switches for Companion mode
+      if ((param == USBJOYS_BTN_MODE_COMPANION) && (switch_npos > 0) && (switch_npos < 3))
+        return switch_npos;
+      return switch_npos + 1;
+    }
     uint8_t lastBtnNumNoCLip() {
       uint8_t last = btn_num + switch_npos;
       // Use one less joystick button for 2POS and 3POS switches for Companion mode