Write Datasets to Battery Archive Format

[WardLT]

After discussing with @ypreger , the next step in integration between this toolkit and the data infrastructure will be the ability to read/write data into Battery Archive format.

That format is described in an sql schema file and the importer tends to read files.

The general theme of the output will be to:

• write different CSV files for each type of data (metadata, timeseries, cycle stats)
• convert the names of columns (though I hope that will not be necessary, and that we can adapt our schema)
• chunk larger files into small enough to ingest into the system without much issue

[WardLT]

To be tested by @ypreger and her team before we close this