[PLAT-3488] Refactored most of the implementation for HTS out of
RedisSimulationSeriesSource into AbstractRedisHistoricalTimeSeriesSource,
so that we can implement a NonVersionedHistoricalTimeSeriesSource.
[PLAT-3488] Use a Redis abstract test case class.

This class will ensure the pool is created and that there is a prefix
that will avoid any form of duplication with other developers.
[PLAT-3488] NonVersionedRedisHistoricalTimeSeriesSource

The primary and initial implementation of the HistoricalTimeSeries
interface has been completed, and basic test cases done.
Additional methods could be implemented if it turns out that they're
actually invoked at runtime; unfortunately there's so much legacy
cruft in HistoricalTimeSeries that it's hard to tell
what is actually necessary to implement.