Add more non-interactive options (CKAN-only install, CKAN + DataStore, extensions, etc.)

[rzmk]

It can be helpful to add more non-interactive options for those who intend to use ckan-devstaller in shareable scripts. For example:

• Installing CKAN only
• Installing CKAN + DataStore
• Installing extensions
• Whether to install certain packages such as OpenSSH or not
• Customizing the sysadmin user details

[rzmk]

See https://ckan-devstaller.dathere.com/docs/builder. We'll want to add customizing the sysadmin details too.