remove "cancel" handling from `create`
remove "cancel" handling from `create`

This patch allows us to avoid doing a roundtrip to the server just to
gereate a string and redirect the user.  It implements the "cancel"
button just with javascript.  This means that clicking "cancel" will
simply take the user to the page they want in 1 request rather than 2
requests (plus RJS).
(transferred from ManageIQ/manageiq@27b47d6dbf433c146454953bbeb8b1b1e79443b1)

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic