RFR: 8275082: Update XML Security for Java to 2.3.0 [v2]

[Weijun Wang]

> Import Apache Santuario 2.3.0 without the secure validation changes since in OpenJDK we are using the `jdk.xml.dsig.secureValidationPolicy` security property for XML Signature secure validation protection.
> 
> Two commits are pushed:
> 
> - 2.3.0: Import 2.3.0 code changes
> - revert: revert the Santuario secure validation changes

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  update comment

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6644/files
  - new: https://git.openjdk.java.net/jdk/pull/6644/files/26a8a428..318a7c89

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6644&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6644&range=00-01

  Stats: 3 lines in 1 file changed: 2 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6644.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6644/head:pull/6644

PR: https://git.openjdk.java.net/jdk/pull/6644