fix(spv): clone block header when creating headers message in message_handler

Updated the message_handler to clone the block header when constructing the headers message. This change ensures that the original block header remains intact and avoids potential issues with ownership and borrowing in the processing flow.

Author: PastaPastaPasta

dash-spv/src/client/message_handler.rs

@@ -241,8 +241,7 @@ impl<
 
                 // 1) Ensure header processing and chain tip update for this block
                 //    Route the header through the sequential sync manager as a Headers message
-                let header = block.header;
-                let headers_msg = NetworkMessage::Headers(vec![header]);
+                let headers_msg = NetworkMessage::Headers(vec![block.header.clone()]);
                 if let Err(e) = self
                     .sync_manager
                     .handle_message(headers_msg, &mut *self.network, &mut *self.storage)