* Refactor: operator hash and inferShape
* Add: hash without shape
* Add: inferShape interface for given input tensors
* Add: construct outputs in op ctor
* Add: comments for matmul
* Add: opType in AttrVector and WorkloadVector
* Chore: _graph -> graph in Op ctor
* Chore: change the "Node" suffix to "Obj"
Co-authored-by: Liyan Zheng <liyan-zheng@outlook.com>