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/core/runtime-api/src/lib.rs

@@ -291,7 +291,7 @@ where
 			self.waiting_requests.push_back((request, receiver));
 
 			if self.waiting_requests.len() > MAX_PARALLEL_REQUESTS * 10 {
-				tracing::warn!(
+				gum::warn!(
 					target: LOG_TARGET,
 					"{} runtime API requests waiting to be executed.",
 					self.waiting_requests.len(),
@@ -372,7 +372,7 @@ where
 
 			let runtime_version = api.api_version::<dyn ParachainHost<Block>>(&BlockId::Hash(relay_parent))
 				.unwrap_or_else(|e| {
-					tracing::warn!(
+					gum::warn!(
 						target: LOG_TARGET,
 						"cannot query the runtime API version: {}",
 						e,
@@ -380,7 +380,7 @@ where
 					Some(0)
 				})
 				.unwrap_or_else(|| {
-					tracing::warn!(
+					gum::warn!(
 						target: LOG_TARGET,
 						"no runtime version is reported"
 					);