Add Camera::IsLeftHanded()

A method that returns true if the camera's coordinate system is left-handed.

src/camera.h

@@ -35,6 +35,13 @@ struct Camera
     const Vector3& GetUp() const;
     void SetUp(const Vector3& up);
 
+    /**
+     * Get the camera's handedness. Left handed is the default.
+     *
+     * @returns `true` if the camera is set up for left-handed coordinates.
+     */
+    bool IsLeftHanded() const;
+
     /**
      * Pan and tilt the camera towards the given point.
      *