Add 'path' field to the 'LoadInstanceEnd' ML listener event

The LoadInstanceEnd ML listener event that is added on the scope of SPARK-23674 has no 'path' field which makes it impossible to determine from what path an ML instance was loaded as well as there is no way to get instance's 'uid' via LoadInstanceStart event.

The LoadInstanceEnd must be changed to include 'path' field. Please, refer SaveInstanceStart and SaveInstanceEnd events. Both of them have `path` but LoadInstanceStart and LoadInstanceEnd are not.