Create XML Schema for the XML documents produced by ut_realtime_reporter #1116

Is your feature request related to a problem? Please describe.

The realtime reporter produces an XML document for every event. These XML documents are not documented.

Describe the solution you'd like

Create a XSD for the XML documents produced by the ut_realtime_reporter. Add documents where necessary and add the schema to the documentation of this project.

Describe alternatives you've considered

As alternative you can consult the following:

• the test cases (e.g. https://github.com/utPLSQL/utPLSQL/blob/develop/test/ut3_user/reporters/test_realtime_reporter.pkb#L154-L194)
• the implementation of the realtime reporter (e.g. for pre-run event: https://github.com/utPLSQL/utPLSQL/blob/develop/source/reporters/ut_realtime_reporter.tpb#L72-L83)
• the model of a consuming application (e.g. https://github.com/utPLSQL/utPLSQL-SQLDeveloper/tree/main/sqldev/src/main/java/org/utplsql/sqldev/model/runner or https://github.com/utPLSQL/utPLSQL-SQLDeveloper/blob/main/images/runner_model.png)
• the implementation of a consuming application (e.g. https://github.com/utPLSQL/utPLSQL-SQLDeveloper/blob/main/sqldev/src/main/java/org/utplsql/sqldev/runner/UtplsqlRunner.java#L157-L175)

These are workarounds. A properly documented XSD would be nicer.

Additional context

The missing XML schema was "detected" during the implementation of the utPLSQL plugin for PL/SQL Developer.