Add gender neutral title "Mx"

bluegeek9 → changed the visibility of the branch 8.x-1.x to hidden.

The name module allows site builders to define a vocabulary for titles.

I am not sure how Mx would be translated.

I would imagine translation would be difficult to languages where there is no established gender-neutral titles. https://en.wikipedia.org/wiki/Gender-neutral_title#Languages lists examples in Japanese and Thai. Unless the Name module is shipping translations, I think we can defer to the consumers of the module to translate or remove any titles they don't wish to use.

I did run the concept of this issue by #diversity-inclusion in Drupal Slack.

Among other gems, Fei wrote:

Because we do still use titles in many settings, I would argue that it's important to have one or two common gender-neutral options OOTB. This is because every single time we are exposed to an unfamiliar thing, it becomes more comfortable. So it's an opportunity to bolster visibility among audiences who may not have much exposure to the concept of gender non-conformance.

Further enhancements would be to provide a "do not use title" option (selectable by someone filling out a form exposing the title sub-field) and a write-in option for the title, but I wanted to keep the scope of this change small to facilitate greater inclusion ASAP, especially for consumers of the module that just leave the default set of provided titles as-is. These enhancements could be follow-up issues, but I mention them for context.