RFR: 8314180: Disable XPath in XML Signatures

[Sean Mullan]

The XPath Transform is rarely used, introduces complexity, and is not recommended by the [XML Signature Best Practices](https://www.w3.org/TR/xmldsig-bestpractices/) document. Applications should use the XPath Transform 2.0 Filter instead, which was designed to be an alternative to the XPath Transform. This change will disable the XPath Transform by default.

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

Commit messages:
 - Initial fix.

Changes: https://git.openjdk.org/jdk/pull/25721/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25721&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8314180
  Stats: 14 lines in 5 files changed: 2 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/25721.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25721/head:pull/25721

PR: https://git.openjdk.org/jdk/pull/25721