gitadora: various fixes for wailing (#513)

## Link to GitHub Issue, if one exists
Fixes #512

## Description of change
Fix digital wailing not being recognized consistently.

Also address the fact that wailing was completely broken when lefty mode
was on. This requires a new option that the user needs to check off in
the configurator since we can't magically guess if the user is holding
the guitar in lefty mode.

- [x] fix downward wail
- [x] digital lefty mode
- [x] implement all of this for arena model i/o
- [x] test dx cab 2p
- [x] lefty toggle in overlay
- [x] fix analog not working for 2p guitar
- [ ] analog lefty mode?

## Testing
Checked GW and GW Delta

src/spice2x/games/gitadora/io.h

@@ -209,6 +209,7 @@ namespace games::gitadora {
     // getters
     std::vector<Button> &get_buttons();
     std::string get_buttons_help();
+    std::string get_analogs_help();
     std::vector<Analog> &get_analogs();
     std::vector<Light> &get_lights();
 }