Function execute_sparse_rows_multiply 

pub fn execute_sparse_rows_multiply<F: DspFloat>(
    client: &Client,
    input: &Handle,
    values: &Handle,
    indices: &Handle,
    output: &Handle,
    channels: usize,
    samples: usize,
    width: usize,
)

output = W · input for a sparse-rows W (values / indices uploaded from SparseRows).