ZKInputs update:

API add slots endpoints

Check feeAmount overflow in API

Update Synchronizer (node) implementation

- Add ZKInputs parser to JSON
- Update ProcessTxs to last go-merkletree version changes
- Add StateDB test to generate ZKInputs to check inside a circom circuit
- Small fix at Til CoordinatorTx.LoadAmount=0

- 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

API config refactor

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 add pending withdraws filter on GET /exits

Update fee tables

Refactor/api exits and auth

Add Til set w minimum flow, add balances tests at StateDB ProcessTxs, small fixes at StateDB

Insert ETH as HistoryDB token

Imp api get full-batches

ProcessTxs fees collct update & tests, and other:

API add bids endpoint

- Update StateDB ProcessTxs fees collection
- Update ProcessTxs tests to last StateDB & Til changes
- Til Blockchain L2Txs remove Nonce generation, update tests accordingly
- Update Til Set to test fees

Refactor/api txs

Add collectedFees in TxProcessor, update sync test

- In Synchronizer test, test all tx types

API Coordinator Refactor

Test L2Txs, ExitTree in synchronizer

StateDB store Idxs with TokenID at the db-key & TxSelector include L1CoordinatorTxs in selections

ProcessTxs return an array of created accounts

API Update tokens endpoint

Add struct get state endpoint

Add ProcessTxs send fees to Coordinator accounts

Update Synchroinzer and tests