chore: restructure sound curve loader to load generic 2D graphs instead

src/ObjCommon/Parsing/GenericGraph2D.h

@@ -0,0 +1,25 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class GenericGraph2DKnot
+{
+public:
+    double x;
+    double y;
+
+    GenericGraph2DKnot() = default;
+
+    GenericGraph2DKnot(const double x, const double y)
+        : x(x),
+          y(y)
+    {
+    }
+};
+
+class GenericGraph2D
+{
+public:
+    std::string name;
+    std::vector<GenericGraph2DKnot> knots;
+};