Add ability to have multiple defaults on the locale picker, like say default languages

Especially in situations where you're dealing with locales that have both country and language like: en-US, es-US, en-CA, fr-CA, en-MX, etc., it could be useful to have an option for default languages set, like: en, es, fr, etc.

This way it can have hierarchy like so: en-US > en > Default. In other words, the more specific takes precedence. So if Default were filled out and neither en, nor en-US are filled out, then en-US would take the value of Default. However, en would take precedence over Default. And if en-US were to be filled out, then that would take precedence, as this is the most specific.