tests: unskip PostgreSQL emulator tests (#2089)

* tests: enable pg system tests for the emulator

Unskip system tests for the PostgreSQL dialect running against the
emulator.

* tests: create pg database

* tests: create types table for pg

* tests: create types table for pg

* tests: create types table for pg

* tests: skip stuck pg tests

* tests: re-enable commented out tests

* force ci

* tests: fix dml tests

* tests: syntax

* tests: lint

Author: thiagotnunes