Fix #1344.

The daemon logs "run successfully" when a test execution completes without an error. Even if the test itself failed.
This PR changes the message and logs the actual test outcome in the daemon stdout.
This is less confusing for users and maintainers.

Example

testground run single --plan=example --testcase=output --builder=docker:go --runner=local:docker --instances=1 --wait

Would print "run finished successfully",
but now will print:

Jun  3 06:27:47.137053  INFO    run finished with outcome = failure (single:0/1)        {"run_id": "cacqjoa87d5grq4abs70", "plan": "example", "case": "output", "runner": "local:docker", "instances": 1}

Todo

• change the logging message
• update the dashboard message
• make sure it is not breaking other parts of the code