POSTGRES_URI_ARGS applied to operator don't apply to generated secrets

[jeffutter]

It looks like the POSTGRES_URI_ARGS settings applied to the operator don't end up here in the resulting secrets. This can be rather important when connecting with something like sslmode=disable, it's likely that if the operator needs that any clients would as well.

The operator should either append that automatically or offer the same setting in PostgresUser.

I suspect one could generate that manually with secretTemplate but it seems less surprising to handle it automatically if it's configured in the operator.