RFR: 8365660: test/jdk/sun/security/pkcs11/KeyAgreement/ tests skipped without SkipExceprion

[Mikhail Yankelevich]

* Skipped exceptions added
* minor cleanup

tests changed: 
test/jdk/sun/security/pkcs11/KeyAgreement/TestDH.java
test/jdk/sun/security/pkcs11/KeyAgreement/UnsupportedDHKeys.java
test/jdk/sun/security/pkcs11/KeyAgreement/TestShort.java
test/jdk/sun/security/pkcs11/KeyAgreement/SupportedDHKeys.java
test/jdk/sun/security/pkcs11/KeyAgreement/TestInterop.java

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Commit messages:
 - JDK-8365660: test/jdk/sun/security/pkcs11/KeyAgreement/ tests skipped without SkipExceprion

Changes: https://git.openjdk.org/jdk/pull/26816/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26816&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365660
  Stats: 49 lines in 5 files changed: 9 ins; 28 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/26816.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26816/head:pull/26816

PR: https://git.openjdk.org/jdk/pull/26816