chore: add log to record mapping between channel and block

This commit adds a new log that prints out the channel ID and corresponding block number whenever a new block is added to a channel. This will help trace and debug the relationship between channels and blocks.

op-batcher/batcher/channel_manager.go

@@ -226,6 +226,8 @@ func (s *channelManager) processBlocks() error {
 		} else if err != nil {
 			return fmt.Errorf("adding block[%d] to channel builder: %w", i, err)
 		}
+		s.log.Debug("Added block to channel", "channel", s.currentChannel.ID(), "block", block)
+
 		blocksAdded += 1
 		latestL2ref = l2BlockRefFromBlockAndL1Info(block, l1info)
 		s.metr.RecordL2BlockInChannel(block)