use a single transaction for each generation when importing data from a file

[altendky]

Purpose:

Improve runtime of insertion to the datalayer db from dat files. This occurs when syncing a new update, for example.

many transactions - full file: 3.6s one transaction - full file: 2.2s

many transactions - delta file: 0.97s one transaction - delta file: 0.49s

Current Behavior:

New Behavior:

Testing Notes: