iidx: delay logic for iidx tt (#669)

## Link to GitHub Issue or related Pull Request, if one exists
Re-implements fix for #181 as it was removed by #668

## Description of change
Add two options to add artificial delay to turntable input. These
operate directly on the input logic (`get_tt`) which is called by I/O
emulation code.

Functionally, it's **identical** to the `Delay (experimental)` option we
had in the analog tab, just moved to Options tab.

## Testing
64 bit tdj: ok
64 bit ldj bi2a: ok
32 bit ldj ezusb: ok

Worth noting that TDJ bi2x_hook polls at 120Hz, bi2a at ~500Hz, and
ezusb at ~170Hz

src/spice2x/launcher/options.cpp

@@ -655,6 +655,26 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .game_name = "Beatmania IIDX",
         .category = "Game Options",
     },
+    {
+        // IIDXTTDelayP1
+        .title = "IIDX TT Delay Frames (Player 1)",
+        .name = "iidxttdelayp1",
+        .desc = "Delays turntable input by number of poll frames. Heavily dependent on what I/O emulation is in use! "
+            "As usual, changing any option requires a restart. Default: 0 (no delay).",
+        .type = OptionType::Integer,
+        .game_name = "Beatmania IIDX",
+        .category = "Game Options (Advanced)",
+    },
+    {
+        // IIDXTTDelayP2
+        .title = "IIDX TT Delay Frames (Player 2)",
+        .name = "iidxttdelayp2",
+        .desc = "Delays turntable input by number of poll frames. Heavily dependent on what I/O emulation is in use! "
+            "As usual, changing any option requires a restart. Default: 0 (no delay).",
+        .type = OptionType::Integer,
+        .game_name = "Beatmania IIDX",
+        .category = "Game Options (Advanced)",
+    },
     {
         // spice2x_IIDXDigitalTTSensitivity
         .title = "IIDX Digital TT Sensitivity",