Adds ability to dynamically find auto-increment id.

Previously, when persisting entities, we always start the
auto-incrementing id at 0, regardless of the entities already in the
table. This commit changes allows us to take the max value for the id column
of a table when finding the autogenerated id to persist.
Yes, this is used to toggle whether we want to automatically generate an id. Our change only runs when this ```autoGenerateId``` is set to true. I think we would still want this check