International telephone element errors are not read by A/T

Fixed issue title...it's been quite a morning!

I've opened a merge request, but I do think there may be deeper problems related to the international telephone input validation holistically including:

1. There seems to be some repetition / contention between the error messaging added by the webform.element.telephone.js library and that which clientside validation adds.
2. The reset method is called on keyup -- this can effectively clear validation messages for keyboard users before they have a chance to hear what the errors are.

Leaving at Needs Work for the above points -- really need maintainer feedback, I think :-).

Cheers!