Tramp: Handle PIN requests from security keys

Tramp: Handle PIN requests from security keys

* doc/misc/tramp.texi (Frequently Asked Questions): Clarify FIDO entry.

* lisp/net/tramp-sh.el (tramp-actions-before-shell)
(tramp-actions-copy-out-of-band):
Use `tramp-security-key-pin-regexp'.

* lisp/net/tramp.el (tramp-security-key-pin-regexp): New defcustom.
(tramp-action-otp-password, tramp-read-passwd): Trim password prompt.
(tramp-action-show-and-confirm-message): Expand for PIN requests.

(cherry picked from commit 8d6a8e573f9a1e4eb9ebbc0ec244907263e61bb8)