fix(css): Maximized visible password area (#6433) r=@shane-tomlinson
fix(css): Maximized visible password area (#6433) r=@shane-tomlinson

Because we now have a 55px wide eyeball for show password, I reduced the right padding on the password field to 58px, so the password field extends right up to the button.
mozilla/fxa-content-server,mozilla/fxa-content-server,mozilla/fxa-content-server