gitadora: option for guitar picking algorithm (#528)

## Link to GitHub Issue, if one exists
n/a

## Description of change
Adds an option to pick from four algorithms for guitar picking input.

The default behavior is being switched from legacy (rising edge only,
always 1 frame of input) to SOCD "prefer recent" algorithm. This makes
it slightly easier to navigate the menu with the guitar.

## Testing
Validated gw, gwdelta, and sdvx just in case.

src/spice2x/launcher/options.h

@@ -103,6 +103,7 @@ namespace launcher {
             GitaDoraArenaSingleWindow,
             GitaDoraLefty,
             GitaDoraWailHold,
+            GitaDoraPickAlgo,
             GitaDoraSubOverlaySize,
             LoadJubeatModule,
             LoadReflecBeatModule,