Dandelion++ Rewrite (#2628)

* reworked the dandelion rewrite (dandelion++)

* fallback to fluff/broadcast if we cannot stem the tx for any reason

* rework stem vs fluff logic during accepting tx

* cleanup docs

* add is_stem to logging

* cleanup

* rustfmt

* cleanup monitor and logging

* rework dandelion monitor to use simple cutoff for aggregation

* transition to next epoch *after* processing tx
so we fluff final outstanding txs

* fluff all txs in stempool if any are older than 30s
aggressively aggregate when we can

* fix rebase onto 1.1.0

* default config comments for Dandelion

* fix code to reflect our tests - fallback to txpool on stempool error

* log fluff and expire errors in dandelion monitor

* cleanup

* fix off by one

* cleanup

* cleanup

* various fixes

* one less clone

* cleanup

config/src/comments.rs

@@ -141,9 +141,17 @@ fn comments() -> HashMap<String, String> {
 	);
 
 	retval.insert(
-		"relay_secs".to_string(),
+		"epoch_secs".to_string(),
 		"
-#dandelion relay time (choose new relay peer every n secs)
+#dandelion epoch duration
+"
+		.to_string(),
+	);
+
+	retval.insert(
+		"aggregation_secs".to_string(),
+		"
+#dandelion aggregation period in secs
 "
 		.to_string(),
 	);
@@ -156,13 +164,6 @@ fn comments() -> HashMap<String, String> {
 		.to_string(),
 	);
 
-	retval.insert(
-		"patience_secs".to_string(),
-		"
-#run dandelion stem/fluff processing every n secs (stem tx aggregation in this window)
-"
-		.to_string(),
-	);
 	retval.insert(
 		"stem_probability".to_string(),
 		"