feat(main): Print channel status when loading it from DB

I was trying to debug a node with several multiplexed channels, and
was finding it a bit difficult to determine which channel index
matches which result of `listpeerchannels` as well as figuring out
what their status was. This just prints the status in string format
when loading the channel from the DB.

Changelog-Changed: wallet: The channel status is printed when loading it from the DB

wallet/test/run-db.c

@@ -34,6 +34,9 @@ void channel_gossip_update(struct channel *channel UNNEEDED)
 /* Generated stub for channel_scid_or_local_alias */
 struct short_channel_id channel_scid_or_local_alias(const struct channel *chan UNNEEDED)
 { fprintf(stderr, "channel_scid_or_local_alias called!\n"); abort(); }
+/* Generated stub for channel_state_name */
+const char *channel_state_name(const struct channel *channel UNNEEDED)
+{ fprintf(stderr, "channel_state_name called!\n"); abort(); }
 /* Generated stub for connect_htlc_in */
 void connect_htlc_in(struct htlc_in_map *map UNNEEDED, struct htlc_in *hin UNNEEDED)
 { fprintf(stderr, "connect_htlc_in called!\n"); abort(); }

wallet/wallet.c

@@ -3194,7 +3194,9 @@ bool wallet_htlcs_load_in_for_channel(struct wallet *wallet,
 	bool ok = true;
 	int incount = 0;
 
-	log_debug(wallet->log, "Loading in HTLCs for channel %"PRIu64, chan->dbid);
+	log_debug(wallet->log,
+		  "Loading in HTLCs for channel %"PRIu64" (state=%s)",
+		  chan->dbid, channel_state_name(chan));
 	stmt = db_prepare_v2(wallet->db, SQL("SELECT"
 					     "  id"
 					     ", channel_htlc_id"