This commit hooks the aquifer restart output facility (output arrays
{I,S,X}AAQ and {I,S,A}CAQ) up to the general "RestartIO" module. If
a simulation run uses analytic aquifers we construct an aquifer
output object at simulation start and store this in an optional<> in
the internal implementation object. Otherwise the optional holds
nullopt. We expand RestartIO::save() to take such an optional by
reference and aggregate/output aquifer information, directly after
the well information, if the optional holds a value. Update callers
accordingly.
d43e358d01