Fixes bug where using Execution the Hive sources no longer append data.

The hack we do in the Hive parquet sources no longer works so this is a work around. The benefit this has is that we can now choose which sources are append and which one's aren't.
Yes. However, when you do that in ebenezer you should look at the SInkMods and probably toggle between sink mode replace and sinkmode keep.

This is is very misleading to users atm.