Build a raw data table

[crasanders]

Currently experiment data is stored in the database as ask/tell messages in the replay table, and as blobs in the strat table, but extracting this data is cumbersome. A new data table should be created that stores this data in a query-friendly format that is guaranteed to be consistent across different versions of AEPsych. This will ensure that data is preserved and accessible even if the AEPsych API changes and we cannot load old pickle files. This table should also be constructed in old dbs using the database --update command.