Setting default openmp settings for MKL kernels (#19136)

Setting default openmp settings for MKL kernels (#19136)

* Change inter op defaults when built with MKL to avoid thread oversubscription

* Bump up default mkl inter_op to be less conservative

* Added default OMP settings that are expected to give reasonable performance when using MKL kernels

* Query CPUID for determining number of hyperthreads per physical core on Intel 64 architectures

* Style fixes

* Buildifier and clang-format style fixes

* Removed use of setenv due to concerns about thread safety