Update Synchronizer (node) implementation

- node:
    - Extend config to add initial variables of the smart contracts used as
      defaults before they are changed via events.
    - In stopped channels, set size 1 so that panics are not witheld until the
      node stops completely.
- common:
    - In Smart Contract variables, comment:
      - `WDelayerVariables.HermezRollupAddress` because it's not needed.
      - `RollupVariables.Buckets` because there are no events for it, and for
        now it's not used.
- historydb:
    - Add functions to get and set smart contract variables.
- db:
    - Add `Rollback` function in `utils.go` to reduce boilerplate in sql
      transaction rollbacks in defers in db functions.
    - Update `rollup_vars` and `auction_vars` (renamed from `consensus_vars`)
      table, and add `wdelayer_vars` table.
- synchronizer:
    - Synchronize WDelayer
    - Handle SC variables properly
- test/ethclient:
    - Add essential implementation of WDelayer

cli/node/cfg.buidler.toml

@@ -18,15 +18,17 @@ URL = "http://localhost:8545"
 
 [Synchronizer]
 SyncLoopInterval = "1s"
+
     [Synchronizer.StartBlockNum]
     Rollup = 1
     Auction = 1
     WDelayer = 1
 
 [SmartContracts]
-Rollup   = "0xD6C850aeBFDC46D7F4c207e445cC0d6B0919BDBe"
-Auction  = "0x038B86d9d8FAFdd0a02ebd1A476432877b0107C8"
-TokenHEZ = "0xf4e77E5Da47AC3125140c470c71cBca77B5c638c"
+Rollup   = "0x6F4e99522F4eB37e0B73D0C0373147893EF12fD5"
+Auction  = "0x5E0816F0f8bC560cB2B9e9C87187BeCac8c2021F"
+WDelayer = "0x5D94e3e7aeC542aB0F9129B9a7BAdeb5B3Ca0f77"
+TokenHEZ = "0x2b7dEe2CF60484325716A1c6A193519c8c3b19F3"
 TokenHEZName = "Hermez Network Token"
 
 [EthClient]
@@ -35,3 +37,64 @@ DeployGasLimit      = 1000000
 GasPriceDiv         = 100
 ReceiptTimeout      = "60s"
 IntervalReceiptLoop = "200ms"
+
+    [Synchronizer.InitialVariables.Auction]
+    DonationAddress = "0x0000000000000000000000000000000000000001"
+    BootCoordinator = "0x0000000000000000000000000000000000000001"
+    DefaultSlotSetBid = [
+        "10000000000000000000",
+        "10000000000000000000",
+        "10000000000000000000",
+        "10000000000000000000",
+        "10000000000000000000",
+        "10000000000000000000",
+    ]
+    ClosedAuctionSlots = 2
+    OpenAuctionSlots = 4320
+    AllocationRatio = [4000, 4000, 2000]
+    Outbidding = 1000
+    SlotDeadline = 20
+
+    [Synchronizer.InitialVariables.WDelayer]
+	# HermezRollupAddress        =
+	HermezGovernanceDAOAddress = "0x0000000000000000000000000000000000000001"
+	WhiteHackGroupAddress      = "0x0000000000000000000000000000000000000001"
+	HermezKeeperAddress        = "0x0000000000000000000000000000000000000001"
+	WithdrawalDelay            = 60
+	EmergencyModeStartingTime  = 0
+	EmergencyMode              = false
+
+    [Synchronizer.InitialVariables.Rollup]
+    FeeAddToken = "10"
+    ForgeL1L2BatchTimeout = 10
+    WithdrawalDelay = 1209600 # 60 * 60 * 24 * 7 * 2
+        # [[Synchronizer.InitialVariables.Rollup.Buckets]]
+        # CeilUSD             = 0
+        # BlockStamp          = 0
+        # Withdrawals         = 0
+        # BlockWithdrawalRate = 0
+        # MaxWithdrawals      = 0
+        # [[Synchronizer.InitialVariables.Rollup.Buckets]]
+        # CeilUSD             = 0
+        # BlockStamp          = 0
+        # Withdrawals         = 0
+        # BlockWithdrawalRate = 0
+        # MaxWithdrawals      = 0
+        # [[Synchronizer.InitialVariables.Rollup.Buckets]]
+        # CeilUSD             = 0
+        # BlockStamp          = 0
+        # Withdrawals         = 0
+        # BlockWithdrawalRate = 0
+        # MaxWithdrawals      = 0
+        # [[Synchronizer.InitialVariables.Rollup.Buckets]]
+        # CeilUSD             = 0
+        # BlockStamp          = 0
+        # Withdrawals         = 0
+        # BlockWithdrawalRate = 0
+        # MaxWithdrawals      = 0
+        # [[Synchronizer.InitialVariables.Rollup.Buckets]]
+        # CeilUSD             = 0
+        # BlockStamp          = 0
+        # Withdrawals         = 0
+        # BlockWithdrawalRate = 0
+        # MaxWithdrawals      = 0

cli/node/main.go

@@ -107,6 +107,7 @@ func getConfig(c *cli.Context) (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
+	// nodeCfg.Synchronizer.InitialVariables.WDelayer.HermezRollupAddress = nodeCfg.SmartContracts.Rollup
 	cfg.node = nodeCfg
 
 	return &cfg, nil