Progress: continue development on database abstraction layer

Progress: continue development on database abstraction layer

It seems cleaner to move the trait-specific do_build operations into the traits.
This will simplify the work needed on the actions shared between each DB operation.
This unlike classfull design, this still allows flexibility to do something completely diffeent if needed by the PostgeSQL language.
Begin some cleanup before I start diving into the alter foreign table code (which is quite extensive).
After seeing how if..thens vs switch..cases, I intend to remove the use of switches (they end up way too ugly and hard to read).
I also intend to make sure that $this->value is only ever assigned once the string has been built (preserving the state on error exit).