Support --fail-if-no-tests flag

[mpkorstanje]

🤔 What's the problem you're trying to solve?

While the empty test suite passes by definition, when running tests in CI all tests may for one reason or another be filtered out. This may be undesirable when the expectation there is at least one test executed.

✨ What's your proposed solution?

Add an --fail-if-no-tests option for the CLI and exit with 2 if no pickles were executed.

📚 Any additional context?

• https://stackoverflow.com/questions/75117874/cucumber-jvm-with-gradle-how-to-fail-the-program-if-an-incorrect-test-name-is-p
• https://junit.org/junit5/docs/current/user-guide/#running-tests-console-launcher

[mpkorstanje]

Actually kinda hard with the current design.