Add track keyframes

TrackMatrix now includes tracks of features involving only keyframes. The API for controlling and accessing these tracks has been created. All is gtested.

include/core/frame/frame_base.h

@@ -80,6 +80,7 @@ class FrameBase : public NodeBase, public std::enable_shared_from_this<FrameBase
         bool isKeyOrAux() const;
 
         // set type
+        void setNonEstimated();
         void setKey();
         void setAux();