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/sender/send_task.rs

@@ -159,7 +159,7 @@ impl SendTask {
 	pub fn on_finished_send(&mut self, authority: &AuthorityDiscoveryId, result: TaskResult) {
 		match result {
 			TaskResult::Failed(err) => {
-				tracing::trace!(
+				gum::trace!(
 					target: LOG_TARGET,
 					?authority,
 					candidate_hash = %self.request.0.candidate_receipt.hash(),
@@ -176,7 +176,7 @@ impl SendTask {
 					None => {
 						// Can happen when a sending became irrelevant while the response was already
 						// queued.
-						tracing::debug!(
+						gum::debug!(
 							target: LOG_TARGET,
 							candidate = ?self.request.0.candidate_receipt.hash(),
 							?authority,
@@ -290,7 +290,7 @@ async fn wait_response_task(
 			TaskFinish { candidate_hash, receiver, result: TaskResult::Succeeded },
 	};
 	if let Err(err) = tx.feed(msg).await {
-		tracing::debug!(
+		gum::debug!(
 			target: LOG_TARGET,
 			%err,
 			"Failed to notify susystem about dispute sending result."