Fix[ntsa::Timestamp]: less operator

[678098]

No description provided.

[678098]

This conflicts with

    if (d_id < other.d_id) {
        return true;
    }

making possible to have A.less(B) == true and B.less(A) == true at the same time.

This should be false similar to

    if (other.d_type < d_type) {
        return false;
    }