Support Digital Ocean hosted PostgreSQL

[hardillb]

Epic

No response

Description

As a: Digital Ocean User

I want to: use a DO hosted PostgreSQL database

So that: I can make use of the hosted services (e.g. backup)

Acceptance Criteria

• [ ] Check for DB environment variables when running setup script
• [ ] Add correct section to flowforge.yml
• [ ] Remove correct section from docker-compose.yml