DPPP doesn't write flags in h5parm

Created by: revoltek

Some combinations of solver+mode do not properly handle flags (i.e. the solver doesn't write any flag). So far I noticed it in DDE+diag and in DIE+fulljones. A check of all modes in both solvers should be done to be sure that flags are always properly saved in h5parms.

At the same time, it would be good to also check if applycal properly propagates all flags back to the MS, this was not the case for a few modes, but needs to be there for all of them.