* WIP input * weights rnn optimization

* concat + slcing + replacing new node works

* WIP unit test case of fusing rnn inputs

* - Added unit test case for fusing rnn input weights
- registered CPURnnMatFusion_v1/v2 in codegen and DEX

* fixed redeclaration of a variable

* Refactored rnn input traformation passes into a single pass

* Refactored CPURnnMatFusion call back functions

* change random generator range to include -ve values in unit test

* address PR comments

* dont fuse if the shape of the data slices dont match