Speed up test_pipe_protocol test

[phw]

Summary

• This is a…
  • Bug fix
  • Feature addition
  • Refactoring
  • Minor / simple change (like a typo)
  • Other
• Describe this change in 1-2 sentences:

Problem

The test_pipe_protocol is extremely slow. Without it the full test suite runs on my system with pytest in ~8 seconds. With test_pipe_protocol enabled in runs 71 seconds.

Solution

• Only test a single message. As there is no message processing here we just need to ensure the sent message gets read
• Reduce timeouts. The timeouts helped with Windows tests. But try to reduce them.
• The check for if message in pipe_listener might help with macOS tests. On macOS sometimes the read seems to return an empty string. In normal use in Picard that is ok. The empty string is not a processed message and the loop will just read the next one. Do the same in tests