[11u] RFR: 8224650: Add tests to support X25519 and X448 in TLS

[Lindenmaier, Goetz]

Hi,

I am downporting this for 11.0.10-oracle parity.
Also, this is needed to test JDK-8171279.
http://cr.openjdk.java.net/~goetz/wr20/8224650-X25519_test-jdk11/01/

The changes to SSLSocketTemplate.java have been downported already:
https://bugs.openjdk.java.net/browse/JDK-8249159
8249159: Downport test rework for SSLSocketTemplate from 8224650

In the new test, I had to remove four Cipher suites that are not 
supported in 11.
I just commented them so in case these Cipher suites are downported
It is more easy to find that they must be enabled in this test.

https://bugs.openjdk.java.net/browse/JDK-8224650
http://hg.openjdk.java.net/jdk/jdk13/rev/ed7851b2d5e4

Best regards,
  Goetz.