RFR: 8347814: Make all imports consistent in the FFM API tests and benchmarks

[Per Minborg]

This PR proposes to make all imports consistent in the FFM API tests and benchmarks.

This is a follow-up PR from https://github.com/openjdk/jdk/pull/22827

Passes tier1-3

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Commit messages:
 - Merge branch 'master' into fix-imports-tests
 - Fix copyright year
 - Fix imports

Changes: https://git.openjdk.org/jdk/pull/23689/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23689&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347814
  Stats: 1239 lines in 155 files changed: 553 ins; 426 del; 260 mod
  Patch: https://git.openjdk.org/jdk/pull/23689.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23689/head:pull/23689

PR: https://git.openjdk.org/jdk/pull/23689