Add an option to localize Toastr messages

[Hyftar]

While you can currently specify a string to use for Toastr messages during the configuration, there's no obvious / easy way to setup a localized string.

I'd like to be able to either localize that string or disable the Toasts all together if that's not possible.

I worked around that issue by adding a CSS rule to hide the formhelper-toast-container element.