Refactor sqllogictest to extract postgres functionality into a separate file

[Omega359]

Is your feature request related to a problem or challenge?

As mentioned in #13936 (comment) as part of #13936 the implementation of sqllogictest.rs with the sqlite changes has resulted in a file with far too many #[cfg(feature = "postgres")] and should be refactored to extract out the postgresql functionality to a separate file.

Describe the solution you'd like

A new file postgres_container.rs is added which contains the postgresql functionality formerly in the sqllogictest.rs file

Describe alternatives you've considered

No response

Additional context

No response

[Omega359]

take

[Omega359]

This is ready to go but I'll wait for #13936 to be merged before creating a PR for it.