Yanchen/nuphar/scatter elems (#1992)
* Added Scatter and ScatterElements to Nuphar
Implemented Scatter (op_ver 9 - 10) and ScatterElements (op_ver 11)
nuphar.
Because TVM's compute is output-oriented, our current implementation
uses extern calls for simplicity.
* fixed build issue after rebase
* remove dead code
* Address CR
* removed dead code
* use GetAttrOrDefault
* Address more CR feedback
* add GetStrides to codegen/common/utils.h
* added a unit test for Bool input data
