A small test harness bundle was recently added that is breaking the docker image build. It could be added to the docker image, but that would introduce a bunch of extraneous test file dependencies. So this tweaks the build to simply skip the test bundle if its primary source file is not found.
Also added some other test fixes along the way:
* make a custom widget test more reliable
* update a localization test now that `pt` exists
* store more log info in artifact on error