[jdk11u-dev] RFR: 8284047: Harmonize/Standardize the SSLSocket/SSLEngine/SSLSocketSSLEngine test templates [v3]

[Antonio Vieiro]

> Backport of [JDK-8284047](https://bugs.openjdk.org/browse/JDK-8284047) from 17 to 11, to improve different templates for SSL tests. This builds on top of #3150 , and will be followed up by backports of JDK-8306014 and JDK-8306015. The changes converts `SSLContextTemplate` into an abstract class from an interface, and moves different methods and constants from `SSLSocketTemplate` into this new base class. It also drops the `SSLSocketSSLEngine` template.
> 
> The backport is not clean, because JDK11 is still using legacy elliptic curves that were removed in JDK16 via [JDK-8252601](https://bugs.openjdk.org/browse/JDK-8252601) but are not in 11. As a consequence the `CA_ECDSA_SECT283R1` and `EE_ECDSA_SECT283R1` are not present in the JDK17 commit, but must still be retained in JDK11.
> 
> Similarlly, `DisabledCurves.java` must still use the `**SECT_283R1` certificates, and not the `**SECP384R1` onesas in 17, since [JDK-8252601](https://bugs.openjdk.org/browse/JDK-8252601) is not in 11.
> 
> Security tests continue to pass:
> 
> 
> ==============================
> Test summary
> ==============================
>    TEST                                              TOTAL  PASS  FAIL ERROR   
>    jtreg:test/jdk:jdk_security                        1361  1361     0     0   
> ==============================
> TEST SUCCESS

Antonio Vieiro has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge master
 - Backport 5e0be4886b2923309a820d2d6230d9071430ebc7
 - Backport 1f3d71b6205a9b9f473b14e6848db2d49d59110d

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

Changes:
  - all: https://git.openjdk.org/jdk11u-dev/pull/3151/files
  - new: https://git.openjdk.org/jdk11u-dev/pull/3151/files/5744e43b..ee63e0c1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=3151&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=3151&range=01-02

  Stats: 1406 lines in 16 files changed: 443 ins; 7 del; 956 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/3151.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/3151/head:pull/3151

PR: https://git.openjdk.org/jdk11u-dev/pull/3151