flag for printing all details of a service

[derhuerst]

This CLI is useful, thanks! But it would be even more helpful if I could get raw data.

For now, I just added a --print-details boolean flag that prints all of service instead of service.fqdn.

I can also imagine more flexible ways to do this:

• Let it print JSON instead, allowing users to filter for props using e.g. jq.
• Let it accept a _.get-style property path, allowing me to get any single property of each service.

What do you think? Thanks for your review time!