Add support for adding database access either via PostgresNIO or Fluent

[adam-fowler]

To see this working clone the template repository, checkout the database branch and call

hb init --template <path to cloned template> <target directory>

Option to add either fluent or postgres-nio support for databases

• Adds creation of client
• Sets up services
• Adds migrate option --db-migrate that runs migrate and exits
• Add .env to setup postgres database details
• Adds docker-compose.yml which will run a Postgres database

Questions:

• Tests require docker-compose.yml to run and have no way to provide a completely reset database. And will also require the database details in the ConfigReader. What do we want to do here? Encourage users to use the repository pattern and not setup a database client for testing?
• Should we provide a CRUD example controller?