RFR: 8320362: Load anchor certificates from Keychain keystore [v4]

[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.

Alexey Bakhtin has updated the pull request incrementally with one additional commit since the last revision:

  Reuse code from addCertificatesToKeystore

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/16722/files
  - new: https://git.openjdk.org/jdk/pull/16722/files/8fdea0f2..15a28d9a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16722&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16722&range=02-03

  Stats: 221 lines in 3 files changed: 76 ins; 83 del; 62 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