Upgrade XML logger to XML 1.1

[rnveach]

Identified at #5163 (comment) ,

We need to upgrade our XML output to 1.1 to support escaping non-printable characters like hex 0x01 and 0x02 found in openjdk projects.

Before we can upgrade though, we must have maven-checkstyle-plugin ugpgrade their support of this as they won't accept the newer version of XML.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-checkstyle-plugin:2.17:check (default-cli) on project postgresql: Unable to read Checkstyle results xml: /pipeline/source/pgjdbc/pgjdbc/target/checkstyle-result.xml: only 1.0 is supported as <?xml version not '1.1' (position: START_DOCUMENT seen <?xml version="1.1"... @1:19) -> [Help 1]

[rnveach]

I have created the issue with maven-checkstyle-plugin at https://issues.apache.org/jira/browse/MCHECKSTYLE-342 .

[romani]

@rnveach , I think it is better to close this PR and wait for plugin to resolve issue.