* Remove some unnecessary calls to create_args in basic and universal GEMM tests
* Remove unnecessary include statements in universal GEMM tests
* Improve compilation time of basic GEMM tests by only compiling the precision variants that we need
* Universal GEMM PrecType should be the same as CDataType
* Improve compilation time of universal GEMM tests by only compiling the precision variants that we need
* Revert to constexpr when defining some constants