Short syntax for wait

There should be a more convenient way to declare a wait condition.

It could be like

• tcp@3://minio:9000
  for method tcp, timeout 3 for service minio on port 9000 or
• log@10://postgres:database system is ready to accept connections
  for method log, timeout 10 for service postgres on message database system is ready to accept connections.

In general the syntax would be:

• <wait-method>@<timeout>://<service>[:special-args-for-wait-method]