FormPrompter is the only production prompter and implements the rich
prompt API, so Ask, AskText and ConfirmDefault become the Prompter
interface and the plain Input/Confirm fallbacks go away.
Confirmations that default to no derive their non-terminal wording
from the prompt, and single deletes share deleteConfirmed for the
prompt, the request and the done line.
Signed-off-by: bircni <bircni@icloud.com>