Some very basic unit level test coverage for associating output at the test case level in JUnit XML files.

Also made some test fixtures for build TestResultProvider instances more reusable.
Enabled generating the JUnit XML file with output per test case.

This is not complete. The actual generation of the XML based on the TestResultsProvider is unit tested and there is functional level coverage when running TestNG tests.

Coverage for JUnit is needed, as well as coverage at the intermediary parts of the results/report generation.

There are also some types to tidy up.