[SUREFIRE-2101] - Fixes 'null' phrased test names with JUnit5 without @DisplayName

[ascopes]

When phrased test names are enabled, but an annotation such as DisplayName
in JUnit5 is missing from the test, the output to the console will now
fall back to using the original name rather than naming the test
'null'.

This amends this behaviour to provide a more meaningful name in these scenarios,
which can be important when migrating a large code base over to using
phrased names incrementally.

An example of the existing output which can be problematic:

---

To make clear that you license your contribution under
the Apache License Version 2.0, January 2004
you have to acknowledge this by using the following check-box.

• I hereby declare this contribution to be licenced under the [Apache License Version 2.0, January 2004](http:https://www.apache.org/licenses/LICENSE-2.0

• As of Sunday 19th June 2022, I have submitted a signed copy of the Apache ICLA to mailto:[email protected] in PDF form.

[andpab]

This pull request fixes the issue for the JUnit5StatelessTestsetInfoReporter, but not for the JUnit5ConsoleOutputReporter.

You can see that in the output of the JUnitPlatformEnginesIT#testJupiterEngineWithDisplayNames. It still has "Running null" in it with your fix.

The reason it doesn't work there is that you adjusted the behaviour for the CategorizedReportEntry and the WrappedReportEntry, but not for the SimpleReportEntry.

I've made an alternative pull request #587 that fixes it in a single place, the TestSetStats class. I think that's more robust.

[slawekjaranowski]

@ascopes thanks
I changed commit message to contains issue number in square brackets 😄