Sufficiency episodes table changes

[MichaelHanksSF]

There are currently three processes that Power Query runs in the Dynamic Sufficiency dashboard that Python would manage more efficiently:

• a process to work out what the most recent 'S' episode (from RNE) is for a given child per row
• a process to work out what the most recent DECOM is for a given child per row
• a process that provides the most recent submission year for a given LA (though this may be redundant as already included in Pipeline: Port Episodes fix to dagster sf-fons-platform#69.

Additionally, we should create a new copy of the episodes table (factPlacementEpisodes) from factEpisodes that follows the logic for only including episodes that correspond to actual placement changes. see regional demand model datacontainer for pre-written logic.