Refactor trivial GEMM case

The case when it is not a matrix multiplication actually.
Convenience overload taking matrix dimension as a tuple
matrixProductSample shall be an iterator

So as to avoid swamping memory by generating all matrices upfront
Make get and put public to ease debugging of buffers
Utility to display the content of one of the buffer

We use a Mathematica format as this makes debugging easier
Utility to copy buffer to an array

This is for debugging purposes
Dead code removal
Fix bug that would materialise when k > kc
Fix bug materialising when k > kc and beta != 1

Clarify documentation and API as a side-effect. After this fix,
the case beta != 1 is a bit less efficient for small matrices.
Note that the important case is beta = 1 (this is the workhorse of
many algorithms): thus change the benchmark to study that case.
Add a random sign to the distribution 2**(uniform integer)
Test larger matrices and test the different beta cases correctly
Add one dimension in the range 32-64 to test fast matrix x matrix
Cleaner way to use generator for matrix x matrix tests
Refactor precondition check for TRSM
Rename file as it will host all Fast BLAS 3 benchmarks
Refactor commonalities to prepare for TRSM benchmark
Capital letter for FromLeft and FromRight enumeration constants
Generate samples to test triangular system solver
Testing fast TRSM against naive TRSM
Benchmark of TRSM: naive vs fast