Dance around early support (#897)

## Link to GitHub Issue or related Pull Request, if one exists
N/A

## Description of change
This PR add initial supports for running Dance aRound in window mode,
with keyboard, cardio supports.

## Testing
- Tested game play under Windows 10 using Kinect V1 with my visionpose
compatible layer (https://github.com/Avimitin/dance-around-anygear)


https://github.com/user-attachments/assets/4b821dcf-751d-4953-b626-4a9491569183

- Tested full game play, user profile saving with Asphyxia

Assisted by AI.

---------

Co-authored-by: Codex <codex@openai.com>

src/spice2x/rawinput/midi.cpp

@@ -9,6 +9,7 @@
 namespace rawinput {
 
     static MidiNoteAlgorithm MIDI_NOTE_ALGORITHM = MidiNoteAlgorithm::V2;
+    bool DISABLE_MIDI = false;
 }
 
 rawinput::MidiNoteAlgorithm rawinput::get_midi_algorithm() {
@@ -37,6 +38,10 @@ void rawinput::set_midi_algorithm(rawinput::MidiNoteAlgorithm new_algo) {
 
 void rawinput::RawInputManager::midi_scan_start() {
 
+    if (rawinput::DISABLE_MIDI) {
+        return;
+    }
+
     // single-flight: only one scan runs at a time. if one is already running, set
     // the pending flag so it rescans once more when it finishes - MIDI hotplug
     // events fire while the slow enumeration is still going and must not be lost.