Always stem local txs if configured that way (unless explicitly fluffed) (#2876)

* always stem local txs if configured that way (unless explicitly fluff from wallet)
this overrides current epoch behavior for txs coming in via "push-api"
rename "local" to "our" txs

* TxSource is now an enum for type safety.

config/src/comments.rs

@@ -210,6 +210,14 @@ fn comments() -> HashMap<String, String> {
 		.to_string(),
 	);
 
+	retval.insert(
+		"always_stem_our_txs".to_string(),
+		"
+#always stem our (pushed via api) txs regardless of stem/fluff epoch (as per Dandelion++ paper)
+"
+		.to_string(),
+	);
+
 	retval.insert(
 		"[server.p2p_config]".to_string(),
 		"#test miner wallet URL (burns if this doesn't exist)