HistoricComponent sends blank initial value before default set via HistoricParamService.list()

[CloudNiner]

We should reorganize the component initialization such that we don't emit a value from this component until we are able to compare params against the results of the API call to get the valid historic params.

PercentileHistoricComponent has the same logic and should be fixed as part of this issue as well.

Currently this issue manifests itself as any chart rendered using these components re-renders both when the initial blank value is set and when the follow-up default value is set.