Support linecomments in junit

With junit, there is a lot of flexibility--almost too much. With most of the junit processors, our existing output works reasonably well. For systems like Cirrus CI, if we use a more pytest-like format, then Cirrus will use GitHub Checks Annotations to mark the source tree in GitHub. However, that pytest-like format looks does not really work for, say, Circle CI. Therefore, it might be useful to provide a one or more switches to either create one or both types of formats for maximum flexibility. Doing this will almost certainly be an incompatible change.