feat: re-implement (native) Gizmo class, expose preserveScaling parameter for setParent, add methods for getting viewport bounding box from renderable entity

thermion_dart/native/include/Aabb2.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+struct Aabb2 {
+    float minX;
+    float minY;
+    float maxX; 
+    float maxY;
+};
+
+typedef struct Aabb2 Aabb2;
+
+#ifdef __cplusplus
+}
+#endif