RFR: 8371184: Improve jpackage test coverage for "--app-image" option

[Alexey Semenyuk]

- Verify that when `--app-image` option is specified, files from the predefined app image are copied verbatim into the output app image (JPackageCommand: add `PREDEFINED_APP_IMAGE_COPY`, update TKit.PathSnapshot class).
 - Clean up redundancies after [8351369: [macos] Use --install-dir option with DMG packaging](https://bugs.openjdk.org/browse/JDK-8351369) fix: remove `JPackageCommand.dmgInstallDir`, simplify InstallDirTest test.
 - Add `LauncherVerifier.launcherDescription()` and use it from LiunuxHelper; extend PropertyFinder class for `LauncherVerifier.launcherDescription()`.
 - Automatically reapply verifications to launchers in the predefined app image to the command referencing the predefined app image through `--app-image` option. Other changes relate to this update.

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Commit messages:
 - Fix compilation error
 - InstallDirTest: simplify
 - Get rid of redundant JPackageCommand.dmgInstallDir; JPackageCommand: add action to verify files from the predefined app image copied in the output bundle verbatim; MacHelper: add isVerbatimCopyFromPredefinedAppImage()
 - LauncherVerifier: fix launcherDescription()
 - Win8282351Test: some refactoring an use PackageTest.usePredefinedAppImage()
 - LinuxHelper: use LauncherVerifier.launcherDescription() to get the description of the launcher
 - LauncherVerifier: use PropertyFinder to get the description of the launcher
 - AdditionalLauncher: use cmd.addVerifyAction(createVerifierAsConsumer(), JPackageCommand.ActionRole.LAUNCHER_VERIFIER);
 - Use PackageTest.usePredefinedAppImage()
 - PropertyFinder: enhance the API
 - ... and 2 more: https://git.openjdk.org/jdk/compare/9f972008...c37d67bf

Changes: https://git.openjdk.org/jdk/pull/28118/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28118&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371184
  Stats: 462 lines in 20 files changed: 272 ins; 80 del; 110 mod
  Patch: https://git.openjdk.org/jdk/pull/28118.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28118/head:pull/28118

PR: https://git.openjdk.org/jdk/pull/28118