refactoring code to use proper views in the UI and turned the camera instance into its own view with callbacks.

Also added in the model for initial use, and working to create the inferences off of TFLite using that view.

lib/utils/camera_view_singleton.dart

@@ -0,0 +1,10 @@
+import 'dart:ui';
+
+class CameraViewSingleton {
+  static double ratio = 0.0;
+  static Size screenSize = const Size(0, 0);
+  static Size inputImageSize = const Size(0, 0);
+
+  static Size get actualPreviewSize =>
+      Size(screenSize.width, screenSize.width * ratio);
+}