[jdk8u-dev] RFR: 8245654: Add Certigna Root CA

[Severin Gehwolf]

Clean backport modulo path changes. Parity with Oracle JDK 8u371.

Testing:
- [x] `jdk/test/sun/security/lib/cacerts/VerifyCACerts.java` and `jdk/test/security/infra/java/security/cert/CertPathValidator`. All pass after fixes in #271 and #270 

Thoughts?

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Commit messages:
 - Backport c8ee076241cc7d83f423683d97ec37f9e0d6ebaa

Changes: https://git.openjdk.org/jdk8u-dev/pull/272/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=272&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8245654
  Stats: 262 lines in 3 files changed: 258 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/272.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/272/head:pull/272

PR: https://git.openjdk.org/jdk8u-dev/pull/272