message: op-node: Provide information with ErrTooManyRLPBytes
diff: @@ -90,7 +90,8 @@ func (co *ChannelOut) AddBlock(block *types.Block) error {
  return err
  }
  if co.rlpLength+buf.Len() > MaxRLPBytesPerChannel {
  - return ErrTooManyRLPBytes
  + return fmt.Errorf("could not add %d bytes to channel of %d bytes, max is %d. err: %w",
  + buf.Len(), co.rlpLength, MaxRLPBytesPerChannel, ErrTooManyRLPBytes)
  }
  co.rlpLength += buf.Len()
  