Make Drafty work with the Title module patch from issue #2267251

Per #2267251-10: Do not rely on "content language" in hook_entity_presave(), the Title module patch in that issue requires that code doing a programmatic entity save and changing the entity title needs to call the Entity Translation handler's setFormLanguage() method before saving.

Since Drafty does a programmatic entity save, it definitely needs to call this method. (In theory it could check if the save is changing the title, and only call the method if it is, but it seems cleaner and less prone to future bugs to just set it always.)

We are running that Title module patch on a site and have seen major bugs as a result (if you edit and save an entity translation twice in a CPS changeset, then after the second save, the translated title gets saved to the English version of the entity, on the live site!). This patch fixes the problem.

This issue is related to #2395793: Remove title module special-casing but not the same thing since it's not clear the old code can be removed yet, even once the above-referenced Title module patch is committed.