Address ZeroK case for Gemm for CPU and CUDA (#22111)
### Description
When K == 0 output a MxN matrix filled with bias if present or filled
with zeros.
This brings it inline with MatMul behavior especially when Gemm is used
to fuse MatMul with Add.
### Motivation and Context
* Comply with numpy spec of MatMul
* Address a case when empty initializers are used for computation.
