[jfx11u] RFR: 8289541: Update ICU4C to 71.1

[Kevin Rushforth]

Nearly clean backport, except for the changes in `gradle/verification.metadata`, since that file doesn't exist in jfx11u.

CI build run on all three platforms.

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Commit messages:
 - 8289541: Update ICU4C to 71.1

Changes: https://git.openjdk.org/jfx11u/pull/118/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx11u&pr=118&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289541
  Stats: 144946 lines in 750 files changed: 10988 ins; 123549 del; 10409 mod
  Patch: https://git.openjdk.org/jfx11u/pull/118.diff
  Fetch: git fetch https://git.openjdk.org/jfx11u pull/118/head:pull/118

PR: https://git.openjdk.org/jfx11u/pull/118