Include usernames in translator credits

[dumbmoron]

Describe the problem

Currently, the output for translator credits includes the translator's email, name, and change count.

Describe the solution you would like

It would be useful for me for automatic translation attribution if the output also included the account username of the translator.

Describe alternatives you have considered

It would probably be possible to pull out the username through some incantation of API calls, but it's not ideal considering this endpoint already has access to this information, and simply omits it.