CaptureMotion: replace origin_frame_ptr_ by capture_origin_ptr_.

SO far, CaptureMotion was storing a pointer to the Frame where its MotionBuffer started. This was the Frame previous to the frame of the capture. The API of CaptureMotion reflected this with

• a const FrameBasePtr & in the constructor
• getter and setter for the origin_frame_ptr_ member.

Very often, algorithms needed to access not the origin frame, but the origin capture associated with the same sensor. This required a call to getCaptureOf(SensorBasePtr).

I find it overall a little odd. Storing the Capture everything seems easier: the Capture is accessed directly, and the Frame is obtained from the capture->getFrame().

So this MR replaces the pointer to Frame to a pointer to CaptureBase.

@joanvallve possibly this interests you as you were having a question about this short ago.

include/core/sensor/sensor_diff_drive.h

@@ -53,15 +53,20 @@ class SensorDiffDrive : public SensorBase
 {
     public:
         SensorDiffDrive(const Eigen::VectorXs& _extrinsics,
-                                 const IntrinsicsDiffDrivePtr& _intrinsics);
+                        const IntrinsicsDiffDrivePtr& _intrinsics);
         WOLF_SENSOR_CREATE(SensorDiffDrive, IntrinsicsDiffDrive, 3);
         virtual ~SensorDiffDrive();
-        IntrinsicsDiffDriveConstPtr getParams() const {return params_diff_drive_;}
+        IntrinsicsDiffDriveConstPtr getParams() const;
 
-    protected:
+    private:
         IntrinsicsDiffDrivePtr params_diff_drive_;
 };
 
+inline wolf::IntrinsicsDiffDriveConstPtr SensorDiffDrive::getParams() const
+{
+    return params_diff_drive_;
+}
+
 } /* namespace wolf */
 
 #endif /* SENSOR_SENSOR_DIFF_DRIVE_H_ */