[jdk21u-dev] RFR: 8328638: Fallback option for POST-only OCSP requests

[Aleksey Shipilev]

Improves JDK OCSP compatibility with some real world OCSP responders. Starts to be a problem since JDK 17 introduced GET OCSP requests. The default behavior is not changed.

The backports are almost clean, I just had to add the import for `Locale` in one of the files. It is added in mainline by [JDK-8312443](https://bugs.openjdk.org/browse/JDK-8312443), which I do not want to backport at the moment, as it changes existing security code.

Additional testing:
 - [x] `jdk_security` pass, including new test cases

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Commit messages:
 - Backport 4a14cba2f1632c5cb91e37a07638ea6d8ad4ec00
 - Backport 614db2ea9e10346475eef34629eab54878aa482d

Changes: https://git.openjdk.org/jdk21u-dev/pull/413/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=413&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328638
  Stats: 128 lines in 5 files changed: 123 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/413.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/413/head:pull/413

PR: https://git.openjdk.org/jdk21u-dev/pull/413