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.cpp

@@ -1020,6 +1020,25 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .game_name = "GitaDora",
         .category = "Game Options",
     },
+    {
+        // GitaDoraPickAlgo
+        .title = "GitaDora Picking Algorithm",
+        .name = "gdpickalgo",
+        .desc = "Select picking algorithm for guitar.\n\n"
+            "recent (default): use SOCD cleaner algorithm that prioritizes recent input\n\n"
+            "legacy: only the rising edge of the pick input is considered; cannot hold pick for menu navigation\n\n"
+            "neutral: if both up and down are pressed, they cancel out\n\n"
+            "raw: no filtering done by spice; game receives both input as-is, possible to input both up and down at the same time",
+        .type = OptionType::Enum,
+        .game_name = "GitaDora",
+        .category = "Game Options",
+        .elements = {
+            {"recent", ""},
+            {"legacy", ""},
+            {"neutral", ""},
+            {"raw", ""}
+        },
+    },
     {
         // GitaDoraSubOverlaySize
         .title = "GitaDora Subscreen Overlay Size",