No debug output in online editor anymore

[mk-mxp]

Since #105 there is no user output (echo or var_dump()) forwarded to the online editor results. There is no test for that, so it wasn't catched in advance.

• [x] Add a test for user output
• [x] Make it possible again to have the output in the results

I also got that feedback from a collegue on CLI. Maybe PHPUnit needs to be configured accordingly?

[mk-mxp]

Investigation:

• The problem is not present for students using the CLI. Nothing changed for them.
• PHPUnit decided to remove <system-out> from JUnit for PHPUnit V10+. There is no replacement.
• It is not possible to suppress all PHPUnit output and let user output shown up. The reason is, that PHPUnit captures all output and controls showing it with its own output creation.
• It is possible to mark tests, that produce output, as failed (--disallow-test-output --fail-on-risky).
• JUnit log file doesn't contain these as failed: <testsuite name="HelloWorldTest" [...] tests="1" assertions="1" errors="0" failures="0" skipped="0" time="0.007922">
• Teamcity log file does contain these tests, but the file must be parsed additionally (| is escape char): ##teamcity[testFailed name='testHelloWorld' message='This test printed output: My |'User üâ|||| output|'|n\Some backslash|nobject(stdClass)#79 (0) {|n}|n' details='' duration='6' flowId='6893']

Conclusion:

• [x] Write additional Teamcity log file during test run
• [x] Add Teamcity log file parsing to junit-handler
• [x] Provide user output from Teamcity log file in JSON result file as expected for V3