make l10n tests more reliable

some tests require resources which can be too slow to load, resulting in a health failure. Excluding timing, we run region code last to allow as much time as possible. Personally, I never see these, but others reliably do. This will become problematic with automated testing cc @PieroV ``` "l10n_media_messages", "l10n_parsererror_direction", // fine - hardcoded top level document element "l10n_validation_messages", // fine - uses DOMParser "l10n_xml_messages", // fine - uses DOMParser "l10n_xml_prettyprint", "l10n_xslt_messages", "l10n_xslt_sort", // fine - uses DOMParser ```