fix the create database part of postgresql.py

[pUrGe12]

Proposed change

Postgresql connected a database, and if it doesn't exist, it needs to create one before connecting to it (this was tried in the except block). Previous code was to connect to the same non-existent database and that won't work, instead we can connect to the default postgres database and create a new database from there.

Type of change

• New core framework functionality
• Bugfix (non-breaking change which fixes an issue)
• Code refactoring without any functionality changes
• New or existing module/payload change
• Localization improvement
• Dependency upgrade
• Documentation improvement

Checklist

• I've followed the contributing guidelines
• I've run make pre-commit, it didn't generate any changes
• I've run make test, all tests passed locally