RFR: 8321206: Make Locale related system properties `StaticProperty` [v2]

[Naoto Sato]

> Currently, Locale-related system properties, such as `user.language` or `user.country`, are initialized when the `Locale` class is loaded. Making them static properties is safer than relying on the `Locale` class loading timing, which could potentially be changed depending on the implementation.

Naoto Sato has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Reflects review comments
 - Merge branch 'master' into JDK-8321206-Locale-static-properties
 - Add exclusions in cdsHeapVerifier for new StaticProperties
 - initial commit

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Changes:
  - all: https://git.openjdk.org/jdk/pull/16986/files
  - new: https://git.openjdk.org/jdk/pull/16986/files/929f339b..35396106

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16986&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16986&range=00-01

  Stats: 38933 lines in 413 files changed: 13835 ins; 23669 del; 1429 mod
  Patch: https://git.openjdk.org/jdk/pull/16986.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16986/head:pull/16986

PR: https://git.openjdk.org/jdk/pull/16986