Remove framework elements from UndefinedStepException stacktrace

[mpkorstanje]

🤔 What's changed?

Stack traces for the UndefinedStepException now look like this:

io.cucumber.junit.platform.engine.UndefinedStepException:
The step 'I have 42 cukes in my belly' is undefined.
You can implement this step using the snippet(s) below:

@Given("I have {int} cukes in my belly")
public void i_have_cukes_in_my_belly(Integer int1) {
    // Write code here that turns the phrase above into concrete actions
    throw new io.cucumber.java.PendingException();
}

        at ✽.I have 42 cukes in my belly(classpath:io/cucumber/skeleton/belly.feature:4)

Where previously they included a long stacktrace.

        at io.cucumber.core.runtime.TestCaseResultObserver.assertTestCasePassed(TestCaseResultObserver.java:69)
        at io.cucumber.junit.platform.engine.TestCaseResultObserver.assertTestCasePassed(TestCaseResultObserver.java:22)
        at io.cucumber.junit.platform.engine.CucumberEngineExecutionContext.lambda$runTestCase$4(CucumberEngineExecutionContext.java:116)
        at io.cucumber.core.runtime.CucumberExecutionContext.lambda$runTestCase$5(CucumberExecutionContext.java:136)
        at io.cucumber.core.runtime.RethrowingThrowableCollector.executeAndThrow(RethrowingThrowableCollector.java:23)
        at io.cucumber.core.runtime.CucumberExecutionContext.runTestCase(CucumberExecutionContext.java:136)
        at io.cucumber.junit.platform.engine.CucumberEngineExecutionContext.runTestCase(CucumberEngineExecutionContext.java:111)
        at io.cucumber.junit.platform.engine.NodeDescriptor$PickleDescriptor.execute(NodeDescriptor.java:168)
        at io.cucumber.junit.platform.engine.NodeDescriptor$PickleDescriptor.execute(NodeDescriptor.java:90)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)

🏷️ What kind of change is this?

• ⚡ New feature (non-breaking change which adds new behaviour)

♻️ Anything particular you want feedback on?

The implementation is not ideal. It effectively duplicates functionality from the io.cucumber.core.runner package, but we can't change that without breaking assumptions made by the plugin system.

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.