Fix storage causes realized_dt #317
Description
It seems like flextoolrunner adds solves that fix storage to the realized_dt (and this is used in some storage related equations in flextool.mod). The unintended consequence is that one gets dispatch results outputted from storage solves (where the aim is just to get storage levels for the dispatch solves). The correct functionality would be to output operational/dispatch results only when realized_periods is set in that solve for that period.