RFR: 8357458: Missing Highlight.js license file

[Hannes Wallnöfer]

Please review a change to add the missing license file for Highlight.js required for the `--syntax-highlight` option. This also updates the tests for legal files and library versions to handle the file correctly.

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Commit messages:
 - 8357458: Missing Highlight.js license file

Changes: https://git.openjdk.org/jdk/pull/25352/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25352&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357458
  Stats: 69 lines in 4 files changed: 51 ins; 0 del; 18 mod
  Patch: https://git.openjdk.org/jdk/pull/25352.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25352/head:pull/25352

PR: https://git.openjdk.org/jdk/pull/25352