forms: Fix validation errors for field `name` matches

For fields with `name`s which are the same as other fields on the new ticket
form (such as `time` used with the new ticket by staff form), ensure that
data from the fields outside the main ticket form ("Ticket Details") is not
mingled with fields inside the form.

Since this is only a problem for web requests, and specifically new ticket
by staff requests, this patch only applies the field name to data matching
for non-web requests.