RFR: 8320362: Load anchor certificates from Keychain keystore

[Alexey Bakhtin]

Please review the proposed fix.

The patch loads system root certificates from the MacOS Keychain with TrustSettings.
It allows to build a trusted certificate path using the MacOS Keychain store only.

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Commit messages:
 - 8320362: Load anchor certificates from Keychain keystore

Changes: https://git.openjdk.org/jdk/pull/16722/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16722&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320362
  Stats: 87 lines in 1 file changed: 64 ins; 11 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/16722.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16722/head:pull/16722

PR: https://git.openjdk.org/jdk/pull/16722