This is the one place where we hand point32 over the wire internally, so
remove it.
This is also our first hsm version change!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Don't include exp directly, use an ifdef in common/bolt12
(like we do for peer and onion wiregen files).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Invoices are signed with our own key, but we use a transient payer_key with a
tweak for invoice_requests (and refunds).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>