Incorrect locale used for REST API requests

[johnbillion]

The REST API request that fires off in the admin area every ten seconds to fetch notifications doesn't have a _locale parameter set. This means when a user has their profile language set to something different to the current site's language they see notifications in the wrong language.

These requests should use ?_locale=user so the response uses the user's chosen language.

[roborourke]

I need to reduce that frequency too. Far too noisy as it stands