Add tabular adapters

[joshsh]

Right now, we have the ability to read and write CSVs and other tabular data as lists of DataRows of cells of the same type. Add to this, the ability to adapt a record type to a type-specific encoder or decoder for rows, producing and consuming records. This has been done externally in Java, but never in Hydra itself.

[joshsh]

Leaving this issue open for now, but most of the functionality exists. Just need a test or demo which shows pairing an annotated schema with the tabular coder.

[joshsh]

The branch has been deleted, but all code is merged into main. Still leaving the task open until we have a test or demo.

[joshsh]

The demo is there. Closing.