🌟 Use env var for default locale on server side.

[djiworks]

Is your feature request related to a problem? Please describe.
Currently when using web UI everything is based on user's locale but on server side, emails for example are in English.
So every emails invitations for team are in English.

Describe the solution you'd like
Why don't you use a simple env var to set this default value ?

Additional context

 /*
    |--------------------------------------------------------------------------
    | Application Locale Configuration
    |--------------------------------------------------------------------------
    |
    | The application locale determines the default locale that will be used
    | by the translation service provider. You are free to set this value
    | to any of the locales which will be supported by the application.
    |
    */

    'locale' => 'en', 
   # May be replaced by this
   'locale' => env('APP_DEFAULT_LANG, 'en'),