RFR: 8375323: Improve handling of the "--app-content" and "--input" options in jpackage

[Alexey Semenyuk]

Change how the values of the "--app-content", "--input", and "--mac-dmg-content" options are handled. Traverse the input directories during the configuration phase, before jpackage creates any output, rather than during the packaging phase.

This change required rework of the cli package to support converting values of any type to any type (`T -> T2`). Previously, it supported only String converters (`String -> T`).

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Commit messages:
 - Update copyright year
 - InOutPathTest: remove tests cases for non-existent paths specified for --app-content and --mac-dmg-content options; AppContentTest: add a test case for --app-content set to the output app image
 - FileUtils: remove redundant functionality
 - Add and integrate RootedPath
 - AppContentTest: don't verify app image if jpackage is expected to fail
 - Support two-step OptionValueConverter
 - Add ValueConverterFunction
 - Change signature of OptionValueConverter.
 - Validator, OptionValueConverter: better javadoc
 - Change signature of ValueConverter::convert()
 - ... and 2 more: https://git.openjdk.org/jdk/compare/20bd178b...46375e6f

Changes: https://git.openjdk.org/jdk/pull/29194/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29194&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375323
  Stats: 2000 lines in 45 files changed: 1420 ins; 293 del; 287 mod
  Patch: https://git.openjdk.org/jdk/pull/29194.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29194/head:pull/29194

PR: https://git.openjdk.org/jdk/pull/29194