Allow setting custom schema when connecting to Postgress

[Korayem]

Is your feature request related to a problem? Please describe.
I tried adding schema param to connect_to_postgres() but Vanna threw an error that it doesnt support it

Describe the solution you'd like
Add a new param schema to connect_to_postgres() for when I want to connect to a different schema within the same DB

Describe alternatives you've considered
No alternative except running multiple databases which increases the cost

Additional context
none at the moment