[jdk17u-dev] RFR: 8368328: CompactNumberFormat.clone does not produce independent instances

[Roland Mesde]

Backporting JDK-8368328: CompactNumberFormat.clone does not produce independent instances. Fixes clone method logic and adds a new test. Ran GHA Sanity Checks (passed) and new test (passed). Patch is clean.

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Commit messages:
 - Backport bdf6853cfdd24176bdddb59b6d7bb85036b94c57

Changes: https://git.openjdk.org/jdk17u-dev/pull/4168/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=4168&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368328
  Stats: 114 lines in 2 files changed: 106 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/4168.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/4168/head:pull/4168

PR: https://git.openjdk.org/jdk17u-dev/pull/4168