Add error symbol/code to sql output when logging output to database

[KyleLilly]

This PR just adds an additional column code to the error table and base_error view. The code is the same as the error symbol generated by enabling verbose output (C, S, e, t). Having the additional column allowed us to easily filter out the queries that were crashing the server.

I wasn't really sure how to handle the database migration so I went ahead and created a v1.2 to v1.3 script but if you had something else in mind or want me to change column names just let me know.

[srajan3012]

Hi @KyleLilly
Can you please help me with how you enabled logging to postgres db?
I am new to postgres, I tried --log-to="postgresql://localhost:5432" but it didnt work for me.

Do i need to setup some tables in the postgres before running sqlsmith?

Thanks in advance.