Add xlatms matrix generator

This PR:

• Adds the lapack xlatms matrix generators that allows to specify the eigen/singular values of the generated matrix
• Add a CORE_xlatm1 vector generator converted from the Lapack version to generate vector of specific eigen/singular values. The prototype may evolve to be called in a parallel generation of the vector.
• Factorize the random number generator to avoid code duplication and reuse in xlatm1