Add speaker numbers to notification of new language requested

[emmapeel2]

On our project in Hosted Weblate we mark the components settings for Add new translation to 'Contact Mantainers'.

This way, when translators ask for a new language, the admins get a nice message with a notification.

But mantainers may not be familiar with the requested language. And hosted.weblate already provides information of the number of speakers of a language (population).

Maybe we can add this information to the Notification for new language requested? This way mantainers will have a better idea of the impact the new language would have.

[nijel]

#16069 adds that, thanks for the suggestion.