Generate a full load in first load if in incremental mode

[edulauer]

When using the function sync_db_2_db for incremental load, if the destination table is empty, it raises an exception:

Destination table empty. Use the full load option.

If it's the first run of the task and the table doesn't exist or is empty, a suggestion is for the framework to execute the full load first and then switch to incremental mode, without requiring human intervention.