RFR: 8330542: Add two JAXP configuration files in preparation for a secure by default configuration [v5]

[Joe Wang]

> Add two sample configuration files:
> 
>   jaxp-strict.properties: used to set strict configuration, stricter than jaxp.properties in previous versions such as JDK 22
> 
>   jaxp-compat.properties: used to regain compatibility from any more restricted configuration than previous versions such as JDK 22

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

  add warning msg that the config files can change or be removed.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18831/files
  - new: https://git.openjdk.org/jdk/pull/18831/files/019c2aee..93b66312

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18831&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18831&range=03-04

  Stats: 8 lines in 2 files changed: 5 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/18831.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18831/head:pull/18831

PR: https://git.openjdk.org/jdk/pull/18831