Xliff is not segmented on import, although it should in some cases

if xliff is NOT coming from another translation tool but from a CMS or e-learning system or the like it is likely that the segmentation is not good enough.

Therefore we have to change translate5s behavior and send all xliff to okapi to, except if it is coming from the following translation tools: translate5 (for example with pixel-length-restriction definitions), Across, Trados Studio, MemoQ. We should implement a namespace-based detection here.