RFR: 8317634: Introduce the ability to exclude modules from dedup-legal-notices plugin of jlink [v3]

[Jaikiran Pai]

> Can I please get a review of this change which proposes to implement the enhancement request noted in https://bugs.openjdk.org/browse/JDK-8317634?
> 
> The change in this commit introduces a new `exclude-modules` argument to the `dedup-legal-notices` jlink plugin. This optional argument takes a comma separated values of module names. These module names are then excluded from the de-duplication of license notice files during image generation.
> 
> Two new test methods have been added to the existing `LegalFilePluginTest` jtreg test case to verify this implementation. Existing tests in `test/jdk/tools/jlink` continue to pass. tier testing is currently in progress.

Jaikiran Pai has updated the pull request incrementally with one additional commit since the last revision:

  minor changes to the text in plugin.properties for the new argument, to render better on command line

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Changes:
  - all: https://git.openjdk.org/jdk/pull/16066/files
  - new: https://git.openjdk.org/jdk/pull/16066/files/510a3ecf..980b371d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16066&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16066&range=01-02

  Stats: 12 lines in 1 file changed: 3 ins; 1 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/16066.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16066/head:pull/16066

PR: https://git.openjdk.org/jdk/pull/16066