* support for fused dense layer with cublasLt, fusion in both fprop and bprop

* fix typo causing syntax error

* add fused GEMM+gelu+GEMM modue

* fix typo for workspace size

* update cublas check for 11600

* add tests for fused dense layer

* fix CUDA 10.x path

* safer guard around CUBLAS constants, remove unreferenced variable

* more guard changes

* guard against cublas version instead of cuda

Co-authored-by: Sukru Eryilmaz <seryilmaz@computelab-dgx1v-32.nvidia.com>