Add Time dimension to TileDB schema

[kylemann16]

Add Time dimension to the TileDB schema. Because of the way we need to use the time traveling abilities of TileDB, we need to group Shatter tasks together in those time slots. This means we need another way to track time. Currently we're using meta data to track that, but it would probably be better to utilize a 3rd dimension for TileDB and add Time there.

This way we can query cells by date, and since we're already requiring that users have a date associated with the Shatter command, we can use that date to ingest the data into TileDB.