Added ORB_SLAM3 support. IMU Filter: added base frame conversion option. (#698)

Referred issues:
#655
https://github.com/introlab/rtabmap_ros/issues/492

Note: IMU not supported yet with ORB_SLAM3.

Commits:
* Added orbslam3 support. UI-Source->IMU filtering: Added base frame conversion option of IMU data to uniformize yaw initialization. Madgwick: fixed yaw initialization accordingly to Z acc.

* fixed regression build error with ORB_SLAM2

* Renamed OdometryORBSLAM2 to OdometryORBSLAM (can be 2 or 3 now)

corelib/include/rtabmap/core/IMU.h

@@ -9,7 +9,8 @@
 #define IMU_H_
 
 #include <opencv2/core/core.hpp>
-#include <rtabmap/utilite/ULogger.h>
+#include <rtabmap/utilite/UEvent.h>
+#include <rtabmap/core/Transform.h>
 
 namespace rtabmap {
 
@@ -60,6 +61,9 @@ public:
 
 	const Transform & localTransform() const {return localTransform_;}
 
+	// apply local transform rotation to data, and set Identity rotation for local transform
+	void convertToBaseFrame();
+
 	bool empty() const
 	{
 		return localTransform_.isNull();