Add StateDB compute nonces on ProcessTx L2Tx, and update StateDB for
type TypeSynchronizer, TypeTxSelector, TypeBatchBuilder

Have BigInt be a proper big value that has 18 decimals

Update test ethclient and coordinator

Update TxProcessor L2Tx logic for case ToIdx==0

Add TxID calculation & New{Layer}Tx Type

Add TxID calculation & New{Layer}Tx Type

New{Layer}Tx methods that compute the `TxID` & `TxType` values from the
transaction values:
- NewL1Tx
- NewL2Tx
- NewPoolL2Tx

Add TxID Scanner & Valuer for database/sql

HistoryDB & L2DB & API packages tests will need to be addapted to the
TestTransaction generation once is done.

Update ethclient contracts & add wdelayer events

* WIP rebase

* Combine both SQL DBs

* API and DB refactor

Update ethclient wdelayer & add auction events

Helper methods for Synchronizer and TX refactor

Idx to 6 bytes (48 bits)

Add TxSelector L2Tx filtering logic

Add GET histroy-transactions endpoint

Add StateDB set & get Idx by EthAddr & BJJ methods

Update common.L1Tx parsers, add test checks

Update ethclient auction & add wdelayer

Change endianness to BigEndian (ಥ﹏ಥ), spec has been updated to achieve
compatibility with js & smart contracts & circuits implementations.

Smart Contracts Data Synchronization

Implement L2DB

Update ethclient

TxSelector GetL2TxSelection & GetL1L2TxSelection integrated with dbs

- GetL2TxSelection & GetL1L2TxSelection integrated with dbs
- Create L1CoordinatorTx of type CreateAccountDeposit when a L2
requires it (and the AccountCreationAuth exists)

Feature/integration

L1Tx Codec

Add contracts & ethclient auction