* - Added sigmoid fusion pass
- added mkldnn emitter code for sigmoid

* - corrected sigmoid expected values
- add layout assignment for sigmoid op

* - added assert's in cpu fusion for sigmoid
- style fix

* remove debug prints

* NGMX-371 #comment addressed PR comments - Added sigmoid unit test case with 3D input ii) support in cpu_emmiter for sigmoid to handle all input shapes

* NGMX-371 #comment use shape_size() to calculate the 1d input size