Reorganize smart contract types, udate eth tests, etc.

- Move smart contract constants and structs for variables to
  common/{ethrollup.go, ethauction.go, ethwdelayer.go}:
    - This removes repeated code of the structs for variables
    - Allows reusing the constants and variables from all modules without
      import cycles
- Remove unused common/scvars.go
- In common.BlockData, split data from each smart contract into a sepparate
  field (Rollup, Auction, WDelayer).  This affects the structures that til uses
  as output, and HistoryDB in the AddBlockSCData.
- In Synchronizer:
    - Pass starting block of each smart contract as config, instead of
      incorrectly using the genesis block found in the acution constant (which
      has a very different meaning)
    - Use variable structs from common instead of an internal copy
    - Synchronize more stuff (resolve some TODOs)
    - Fix some issues found after initial testing with ganache
- In eth:
    - In auction.go: Add method to get constants
    - Update README to use ganache instead of buidlerevm as local blockchain
      for testing
    - Update env variables and test vectors to pass the tests with the
      deployment in the ganache testnet.
    - Use ethereum keys derived from paths (hdwallet) in testing to avoid
      hardcoding private keys and generate the same keys from a mnemonic used
      in the ganache tesnet.

api/state.go

@@ -3,15 +3,14 @@ package api
 import (
 	"github.com/hermeznetwork/hermez-node/common"
 	"github.com/hermeznetwork/hermez-node/db/historydb"
-	"github.com/hermeznetwork/hermez-node/eth"
 )
 
 // Status define status of the network
 type Status struct {
-	Network           historydb.Network     `json:"network"`
-	Metrics           historydb.Metrics     `json:"metrics"`
-	Rollup            eth.RollupVariables   `json:"rollup"`
-	Auction           eth.AuctionVariables  `json:"auction"`
-	WithdrawalDelayer eth.WDelayerVariables `json:"withdrawalDelayer"`
-	RecommendedFee    common.RecommendedFee `json:"recommendedFee"`
+	Network           historydb.Network        `json:"network"`
+	Metrics           historydb.Metrics        `json:"metrics"`
+	Rollup            common.RollupVariables   `json:"rollup"`
+	Auction           common.AuctionVariables  `json:"auction"`
+	WithdrawalDelayer common.WDelayerVariables `json:"withdrawalDelayer"`
+	RecommendedFee    common.RecommendedFee    `json:"recommendedFee"`
 }