Audit dbt default macros vs dbt-vertica macros

[arosychuk]

There are a lot of macros that may or may not be supported by the dbt-vertica implementation.

Suggestion of doing a full audit, to see what is implemented, and what is not.

https://github.com/dbt-labs/dbt-core/tree/main/core/dbt/include/global_project/macros

[arosychuk]

I've started a full audit of this, and have refactored the current adapter.sql into the same format the dbt global_project/macros models the functions there. Hopefully this can help us stay on track of what changes are added per each release. I feel the adapter tests are okay, though I feel there are a lot of functions that are NOT being tested at the moment, that we should also include or evaluate.