<i18n dev> RFR: 8349493: Replace sun.util.locale.ParseStatus usage with java.text.ParsePosition

[Justin Lu]

Please review this PR which removes  _sun.util.locale.ParseStatus_ which is a Locale helper class used for parsing language tags.

Such usages should be replaced by _java.text.ParsePosition_ which has almost 1 to 1 behavior. Note that this cleanup changes the exception message in `Locale.caseFoldLanguageTag(String)` to no longer be prepended by `"Ill formed tag: "`. As such, a CSR is filed to address the compatibility aspect.

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Commit messages:
 - init

Changes: https://git.openjdk.org/jdk/pull/23474/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23474&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349493
  Stats: 137 lines in 3 files changed: 12 ins; 78 del; 47 mod
  Patch: https://git.openjdk.org/jdk/pull/23474.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23474/head:pull/23474

PR: https://git.openjdk.org/jdk/pull/23474