chore: log message id if send queue full instead of full raw message

Fixes #6252

Reduce log size for "Send Queue full" warnings by avoiding printing large message data.

Previously, when the send queue was full, the warning log would print the entire `RpcOut` using its `Debug` implementation, which included the complete `RawMessage` with potentially massive byte arrays (`data`, `signature`, `key` fields). In high-traffic scenarios, this resulted in extremely large log files and unnecessary disk I/O.

This PR introduces a `RpcLog` wrapper struct with a custom `Debug` implementation that:

- For `Publish` and `Forward` variants: logs only the essential debugging information (`message_id`, `topic`, `source`, `sequence_number`, `validated`) while omitting the large byte arrays (`data`, `signature`, `key`, and `timeout`)
- For other variants (`Subscribe`, `Unsubscribe`, `Graft`, `Prune`, `IHave`, `IWant`, `IDontWant`): logs normally as they don't contain large data

This change significantly reduces log file sizes in high-load scenarios while maintaining all useful debugging information for troubleshooting.

Pull-Request: #6263.

Author: IronJam11

protocols/gossipsub/CHANGELOG.md

@@ -1,4 +1,8 @@
 ## 0.50.0
+
+- Reduce log size by implementing custom Debug for RawMessage that logs data length instead of full byte arrays.
+  See [PR 6263](https://github.com/libp2p/rust-libp2p/pull/6263)
+
 - Log when sending and receiving messages.
   See [PR 6234](https://github.com/libp2p/rust-libp2p/pull/6234)
 

protocols/gossipsub/src/types.rs

@@ -123,7 +123,7 @@ pub enum PeerKind {
 }
 
 /// A message received by the gossipsub system and stored locally in caches..
-#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Clone, PartialEq, Eq, Hash)]
 pub struct RawMessage {
     /// Id of the peer that published this message.
     pub source: Option<PeerId>,
@@ -147,6 +147,20 @@ pub struct RawMessage {
     pub validated: bool,
 }
 
+impl fmt::Debug for RawMessage {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("RawMessage")
+            .field("source", &self.source)
+            .field("data length", &self.data.len())
+            .field("sequence_number", &self.sequence_number)
+            .field("topic", &self.topic)
+            .field("signature", &self.signature)
+            .field("key", &self.key)
+            .field("validated", &self.validated)
+            .finish()
+    }
+}
+
 impl PeerKind {
     /// Returns true if peer speaks any gossipsub version.
     pub(crate) fn is_gossipsub(&self) -> bool {