first try to add B^T * M * B as a test
Added six operations using blas and own implementation.

- vtav (v^T * A * v: deploying a temporary vector, gemv and dot)
- vtb_product (v^T * B: deploying gemv)
- vtv_product (v^T * v: deploying dot)
- vtu_product (v^T * u: deploying dot)
- vutb_product (v * u^T * B: deploying own code for init a temp and gemm)
- ata_product (A^T * A: deploying gemm).
Added new benchmark program main_vecmatvec.cpp.