observability: tracing gum, automatically cross ref traceID (#5079)

* add some gum

* bump expander

* gum

* fix all remaining issues

* last fixup

* Update node/gum/proc-macro/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* change

* netowrk

* fixins

* chore

* allow optional fmt str + args, prep for expr as kv field

* tracing -> gum rename fallout

* restrict further

* allow multiple levels of field accesses

* another round of docs and a slip of the pen

* update ADR

* fixup lock fiel

* use target: instead of target=

* minors

* fix

* chore

* Update node/gum/README.md

Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>

polkadot/node/network/dispute-distribution/src/receiver/mod.rs

@@ -168,7 +168,7 @@ where
 			match log_error(self.run_inner().await) {
 				Ok(()) => {},
 				Err(fatal) => {
-					tracing::debug!(
+					gum::debug!(
 						target: LOG_TARGET,
 						error = ?fatal,
 						"Shutting down"
@@ -212,7 +212,7 @@ where
 		// Immediately drop requests from peers that already have requests in flight or have
 		// been banned recently (flood protection):
 		if self.pending_imports.peer_is_pending(&peer) || self.banned_peers.contains(&peer) {
-			tracing::trace!(
+			gum::trace!(
 				target: LOG_TARGET,
 				?peer,
 				"Dropping message from peer (banned/pending import)"