Add mechanism to run JDK 17 (Records) tests optionally, similar to jackson-databind

[cowtowncoder]

(note: offshoot from #517)

Currently we cannot add test cases for Record-handling, in Jackson 2.x, due to JDK baseline being Java 8 still.
But there is a way to do this; used f.ex by jackson-databind.
This is relatively simple by:

1. Adding tests under src/test-jdk17/java/
2. Using specific Maven profile to conditionally include this test source directory if (and only if) running on JDK 17+

It'd be good to be able to add specific Records-with-XML test cases.

[cowtowncoder]

cc @JooHyukKim WDYT?

[JooHyukKim]

Yup, totatlly makes sense. I can spare some time today, to set things up.