[8u] RFR: 8220657: JFR.dump does not work when filename is set

[Ekaterina Vergizova]

Hello,
I would like to backport JFR issue 8220657 to 8u.

JBS: https://bugs.openjdk.java.net/browse/JDK-8220657
Original patch: https://hg.openjdk.java.net/jdk/jdk/rev/bd613b97c7c8
Webrev for 8u: https://cr.openjdk.java.net/~apetushkov/jfr_backports_katya/8220657/webrev.00/

The patch applies cleanly, but the added test TestJcmdDumpWithFileName.java requires some adjustments to pass under 8u:
- the test tags are adjusted
- ProcessHandle.current().pid() calls replaced by ProcessTools.getProcessId()
- Path.of() calls replaced by their 8u analogue Paths.get()
- unsupported syntax `try (stream)` replaced by standard try-with-resources

Tested with tier1 and jdk.jfr tests on Linux and Windows, the added test TestJcmdDumpWithFileName.java failed before the fix and passes after.

Thanks,
Ekaterina