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/launcher/options.cpp

@@ -978,6 +978,26 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .category = "Game Options",
         .elements = {{"1", "DX"}, {"2", "SD"}, {"3", "SD2 - white cab"}},
     },
+    {
+        // GitaDoraLefty
+        .title = "GitaDora Lefty Guitar (for Digital Wailing)",
+        .name = "gdlefty",
+        .desc = "Enables lefty mode, flipping motion sensor directions. Default: off.\n\n"
+            "Without this option, enabling LEFT in the game option will continuously trigger UP wail.\n\n"
+            "Has no effect if you are using analog bindings for X/Y axis; expectation is that your controller "
+            "handles this correctly (most do not, however).\n\n"
+            "As always, remember to restart the game after changing options. If you need to change in the game, "
+            "use the I/O panel overlay window",
+        .type = OptionType::Enum,
+        .game_name = "GitaDora",
+        .category = "Game Options",
+        .elements = {
+            {"off", "both righty"},
+            {"p1", "p1 is lefty"},
+            {"p2", "p2 is lefty"},
+            {"both", "both lefty"},
+        },
+    },
     {
         .title = "Force Load Jubeat Module",
         .name = "jb",