⏫Lots of little improvements to import script for PostgreSQL

Looked through the logs top issues faced by users when importing, and made lost of improvements to the import script. 

All DBMS

  • Handle Aliases like int2, int4, int8, numeric etc.
  • Parse CREATE INDEX and CREATE UNIQUE INDEX statements
  • More instructive error logs for when the import fails

PostgreSQL

  • Added missing enum data type
  • Parse character varying data type (previously only understood varchar)
  • Differentiate timestamp and time with/without TIME ZONE