Need function to return object element looked up by path with the path provided as a STRING.

To improve dynamic object interrogation we need a function that accepts an object and a field-path provided as a string and returns the appropriate value.  This will allow object interrogation using parameters and will support extending the the field reference syntax.  The idea is that results from for example OBJECT_PATHS could be used to look up individual field values in a simpler form than passing such results as pattern arguments to OBJECT_PAIRS_NESTED etc.