* Update web sso content to indicate window OK to close
This is done after the authResult handoff message is delivered to the
extension. It is not possible to close the window from javascript as
closing a window is limited to the script that opened it.
If we maintain a reference to the web window, it should be possible to
subscribe to the authResult message and close the web windows from the
browser.
* Use i18n for close tab message
* delete cookie after it is used
Co-authored-by: Matt Gibson <mdgibson@Matts-MBP.lan>