Backport fixes to 5.5.2

[sbrannen]

• Create release notes document for 5.5.2 in the 5.5.x branch
• Backport Some published artifacts contain module-info.class instead of module-info.java #2003 to 5.5.x
• Backport JupiterTestEngine crashes if JUnit 4 is on the classpath but Hamcrest is not #2004 to 5.5.x

[sbrannen]

in progress

[sbrannen]

Done.

See latest commits for details: https://github.com/junit-team/junit5/commits/releases/5.5.x