Break out Features from fb data stream; add dist_coeffs; name cleanup

Passed through yapf, buildifier, clang-format

Send two separate messages, one with detailed features, one without

Change-Id: I70b2bca2d647cd03e2bc538a9dee68ed8155355a
diff --git a/y2020/vision/sift/sift_training.fbs b/y2020/vision/sift/sift_training.fbs
index 7391e76..d4fa740 100644
--- a/y2020/vision/sift/sift_training.fbs
+++ b/y2020/vision/sift/sift_training.fbs
@@ -10,6 +10,10 @@
   // from the target to the field. See CameraPose in :sift_fbs for details of
   // the conventions of this.
   field_to_target:TransformationMatrix;
+
+  // 2D image coordinate representing target location on the training image
+  target_point_x:float;
+  target_point_y:float;
 }
 
 // Represents the information used to match incoming images against.