Switch view/transclusion of translated titles to a mecanism based on the "fr-title" field presence

Transclusion/view of an optional (but recommended) `fr-title` field allows more uses (title rendering through ViewTemplate, Table of Content, timelines, or Search).

We initially tried to expand the use of the optional `caption` field to view and transclude fr-FR translated titles, but it was pushing the envelope, as the function of the caption field had mostly been to get a shorter label in case of need (like in tabs). 

(Sorry for the 22568bbbfb778c4a90b51d7bea63279f697f4acd "Tag fix" 2nd coming: it is redundant with 1015196817ebd948ccb1015b5f47003af2f001b7, but somehow got embedded with this push).