[WIP] Fix ban by software version, some other under-hood changes

- Use updated version of upstream go-xmpp + fixes on client-side
- Introduce golangci-lint v2 + fixes
- Move especially noisy debugging stuff to separate config handles to be able to switch them off
- Add a bit debug to ban by software path

internal/jabber/read_config.go

@@ -261,6 +261,7 @@ func (j *Jabber) ReadConfig() error { //nolint:gocognit,gocyclo
 			log.Info("loglevel not defined in config, using info")
 		}
 
+		// sampleConfig.DebugLib = false
 		// sampleConfig.Log = "" if not set.
 
 		j.C = sampleConfig