Deprecate pay_for_offer_from_human_readable_name

While its cool to have a super trivial API to initiate payment to
a `HumanReadableName`, most wallets ultimately support multiple
payment instruction formats (eg on-chain) or multiple HRN
resolution schemes (eg LN-Address). Thus, we generally don't expect
this API to get a lot of use.

Meanwhile, we've now ended up with both a
`ChannelManager::pay_for_offer_from_hrn` and
`ChannelManager::pay_for_ofer_from_human_readable_name`, which is
incredibly confusing.

Here, we deprecate `pay_for_offer_from_human_readable_name`,
pushing folks to the `bitcoin-payment-instructions` crate instead.
Because it has outbound payment states associated with it it may be
some time before we can fully remove all the pieces of it, sadly.

Author: TheBlueMatt

lightning-dns-resolver/src/lib.rs

@@ -388,6 +388,7 @@ mod test {
 		let amt = 42_000;
 		let mut opts = OptionalOfferPaymentParams::default();
 		opts.payer_note = payer_note.clone();
+		#[allow(deprecated)]
 		nodes[0]
 			.node
 			.pay_for_offer_from_human_readable_name(name, amt, payment_id, opts, resolvers)

lightning/src/ln/channelmanager.rs

@@ -12600,13 +12600,10 @@ where
 	/// Pays for an [`Offer`] looked up using [BIP 353] Human Readable Names resolved by the DNS
 	/// resolver(s) at `dns_resolvers` which resolve names according to [bLIP 32].
 	///
-	/// If the wallet supports paying on-chain schemes, you should instead use
-	/// [`OMNameResolver::resolve_name`] and [`OMNameResolver::handle_dnssec_proof_for_uri`] (by
-	/// implementing [`DNSResolverMessageHandler`]) directly to look up a URI and then delegate to
-	/// your normal URI handling.
-	///
-	/// Alternatively, the [`bitcoin-payment-instructions`] crate provides an implementation of
-	/// much of this logic, and may be useful to decode and resolve payment instructions generally.
+	/// Because most wallets support on-chain or other payment schemes beyond only offers, this is
+	/// deprecated in favor of the [`bitcoin-payment-instructions`] crate, which can be used to
+	/// build an [`OfferFromHrn`] and call [`Self::pay_for_offer_from_hrn`]. Thus, this method is
+	/// deprecated.
 	///
 	/// # Payment
 	///
@@ -12638,6 +12635,7 @@ where
 	/// [`PaymentFailureReason::UserAbandoned`]: crate::events::PaymentFailureReason::UserAbandoned
 	/// [`PaymentFailureReason::InvoiceRequestRejected`]: crate::events::PaymentFailureReason::InvoiceRequestRejected
 	#[cfg(feature = "dnssec")]
+	#[deprecated(note = "Use bitcoin-payment-instructions and pay_for_offer_from_hrn instead")]
 	pub fn pay_for_offer_from_human_readable_name(
 		&self, name: HumanReadableName, amount_msats: u64, payment_id: PaymentId,
 		optional_params: OptionalOfferPaymentParams, dns_resolvers: Vec<Destination>,