<i18n dev> RFR: 8354344: Test behavior after cut-over for future ISO 4217 currency

[Justin Lu]

Please review this PR which improves the _ValidateISO4217_ Currency test by adding testing of future currencies after the transition date.

This is done by creating a patched version of Currency that replaces `System.currentTimeMillis()` calls with a mocked value equivalent to `Long.MAX_VALUE`. A module patch is then applied to supply the new Currency class files.

As the test tracks the ISO 4217 data, manual testing of this change can be done by modifying the cut-over year from 2025 to 2026 for the `CW=ANG;2025-04-01-04-00-00;XCG` entry for both the JDK and test data.

Doing so results in behavior such as,
1st test - CW returns the currency ANG.
2nd test - CW returns the currency XCG.

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Commit messages:
 - shorten the ClassFile logic
 - init

Changes: https://git.openjdk.org/jdk/pull/24701/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24701&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354344
  Stats: 92 lines in 1 file changed: 87 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/24701.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24701/head:pull/24701

PR: https://git.openjdk.org/jdk/pull/24701