Add/move code into kutil library

src/modules/kutil/coord.h

@@ -0,0 +1,14 @@
+#pragma once
+
+namespace kutil {
+
+template <typename T>
+struct coord
+{
+	T x, y;
+	coord() : x(T{}), y(T{}) {}
+	coord(T x, T y) : x(x), y(y) {}
+	T size() const { return x * y; }
+};
+
+} // namespace kutil