test: improve console output of tls-server-verify

When running in parallel, it is not easy to identify what server and
client failed when the test fails. This adds identifiers to all lines
of console output.

Fixes: https://github.com/nodejs/io.js/issues/1461
PR-URL: https://github.com/nodejs/io.js/pull/1836


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>