ops: revise tpetra block matrix-vector product

[mzuzek]

refs #446

[mzuzek]

@fnrizzi

Overloads

For y = alpha * op(A) * x + beta * y there are level-2 pressio::ops::product() implementations:

A	x	y	mode
Tpetra::BlockMultiVector	Teuchos::SerialDenseVector	Tpetra::BlockVector	nontranspose
Tpetra::BlockMultiVector	Eigen vector or expression	Tpetra::BlockVector	nontranspose
Tpetra::BlockMultiVector	Kokkos vector or expression	Tpetra::BlockVector	nontranspose
Tpetra::BlockMultiVector	Tpetra::BlockVector	Eigen vector or expression		transpose
Tpetra::BlockMultiVector	Tpetra::BlockVector	Kokkos vector or expression		transpose

Note: unlike in Epetra, there is no overload storing in Teuchos vector

Test coverage

Epetra level-2 implementations of pressio::ops::product() are tested with (A is always Tpetra::BlockMultiVector in all tests):

test	x	y	mode
ops_tpetra_block.mv_prod_teuchos_vector	Teuchos vector	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_prod_eigen_vector	Eigen vector	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_prod_eigen_span	Eigen span	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_prod_eigen_diag	Eigen diag	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_prod_eigen_vector	Kokkos vector	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_prod_eigen_span	Kokkos span	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_prod_eigen_diag	Kokkos diag	Tpetra::BlockVector	nontranspose
ops_tpetra_block.mv_T_vector_storein_eigen_vector	Tpetra::BlockVector	Eigen vector	transpose
ops_tpetra_block.mv_T_vector_storein_eigen_span	Tpetra::BlockVector	Eigen span	transpose
ops_tpetra_block.mv_T_vector_storein_eigen_diag	Tpetra::BlockVector	Eigen diag	transpose
ops_tpetra_block.mv_T_vector_storein_kokkos_vector	Tpetra::BlockVector	Kokkos vector	transpose
ops_tpetra_block.mv_T_vector_storein_kokkos_span	Tpetra::BlockVector	Kokkos span	transpose
ops_tpetra_block.mv_T_vector_storein_kokkos_diag	Tpetra::BlockVector	Kokkos diag	transpose