RFR: 8360774: Use text representation of normalization data files

[Naoto Sato]

The ICU4J component currently stores binary data files directly in the repository. This change replaces them with base64-encoded text files and converts them to binary during the build process

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/26027/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26027&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360774
  Stats: 92 lines in 8 files changed: 91 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/26027.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26027/head:pull/26027

PR: https://git.openjdk.org/jdk/pull/26027