Add CiTrace recording support.

This is exposed in the GUI as a new "CiTrace Recording" widget.

Playback is implemented by a standalone 3DS homebrew application (which only runs reliably within Citra currently; on an actual 3DS it will often crash still).

src/video_core/debug_utils/debug_utils.h

@@ -14,6 +14,8 @@
 
 #include "common/vector_math.h"
 
+#include "core/tracer/recorder.h"
+
 #include "video_core/pica.h"
 
 namespace Pica {
@@ -129,6 +131,8 @@ public:
     Event active_breakpoint;
     bool at_breakpoint = false;
 
+    std::shared_ptr<CiTrace::Recorder> recorder = nullptr;
+
 private:
     /**
      * Private default constructor to make sure people always construct this through Construct()