[jdk21u-dev] RFR: 8350102: Decouple jpackage test-lib Executor.Result and Executor classes

[Goetz Lindenmaier]

I backport this for parity with 21.0.10-oracle.

-------------

Commit messages:
 - backport 3487f8cbd55b06d332d897a010ae8eb371dd4956

Changes: https://git.openjdk.org/jdk21u-dev/pull/2311/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2311&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350102
  Stats: 48 lines in 3 files changed: 15 ins; 7 del; 26 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2311.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2311/head:pull/2311

PR: https://git.openjdk.org/jdk21u-dev/pull/2311