follow list fetching test and related changes and fixes.

- make BatchedSubManyEose() use a single duplicate id index and use it for replaceable loaders;
- fixes parsing follow entry from kind:3 events (and others);
- adds a "cause" to most cancelation errors in relay/pool;
- remove the inherent cache from dataloader (we have our own hopefully);
- increase max frame size we can read from any websocket to 2**18 (262k), which gives over 2000 item lists.

sdk/lists_profile.go

@@ -48,11 +48,11 @@ func parseProfileRef(tag nostr.Tag) (fw ProfileRef, ok bool) {
 		if _, err := url.Parse(tag[2]); err == nil {
 			fw.Relay = nostr.NormalizeURL(tag[2])
 		}
+
 		if len(tag) > 3 {
 			fw.Petname = strings.TrimSpace(tag[3])
 		}
-		return fw, true
 	}
 
-	return fw, false
+	return fw, true
 }