fix: idle connections and max connection issue

[biraluu]

CHANGE LOG

1. Added a middleware to close idle connections
2. Fine tuned gunicorn processes for optimized connectivity
3. integrated options for postgresql. (connect_timeout is a PostgreSQL-specific option, but during the Docker build, it tries to use SQLite (the default). SQLite doesn't support the connect_timeout option so needed to conditionally add the OPTIONS only for PostgreSQL).