More sparse operations support

[alyst]

This PR adds support for more SparseMKL operations:

• dense := sparse * sparse (spmmd!(), sp2md!())
• sparse := sparse * sparse (including the in-place one that can optionally disable checks for the sparsity structure) (spmm!(), sp2m!())
• dense := X * A * X^T (syprd!())
• dense := X * X^T (syrk!())