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/launcher.cpp

@@ -609,6 +609,17 @@ int main_implementation(int argc, char *argv[]) {
     if (options[launcher::Options::GitaDoraTwoChannelAudio].value_bool()) {
         games::gitadora::TWOCHANNEL = true;
     }
+    if (options[launcher::Options::GitaDoraLefty].is_active()) {
+        const auto text = options[launcher::Options::GitaDoraLefty].value_text();
+        if (text == "p1") {
+            games::gitadora::P1_LEFTY = true;
+        } else if (text == "p2") {
+            games::gitadora::P2_LEFTY = true;
+        } else if (text == "both") {
+            games::gitadora::P1_LEFTY = true;
+            games::gitadora::P2_LEFTY = true;
+        }
+    }
     if (options[launcher::Options::LoadDDRModule].value_bool()) {
         attach_ddr = true;
     }