Add circuit configuration to node config

- Remove MaxL1CoordTxs parameter from the TxSelector because this parameter
  doesn't exist
- Use ChainID in l1tx byte encoding
- Pass txprocessor configuration to batch builder via an existing parameter

cli/node/cfg.buidler.toml

@@ -63,6 +63,10 @@ Path = "/tmp/iden3-test/hermez/batchbuilder"
 [[Coordinator.ServerProofs]]
 URL = "http://localhost:3000/api"
 
+[Coordinator.Circuit]
+MaxTx = 512
+NLevels = 32
+
 [Coordinator.EthClient]
 CallGasLimit        = 300000
 DeployGasLimit      = 1000000