* WIP: rebase

* Make nullable fields use pointers

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.

* WIP rebase

* Combine both SQL DBs

* API and DB refactor

Update tx testing generation:
- add new batch lexic to tx-test language
- add coordinatorL1Txs generation to tx-test
- add SetTest0 code to generate test L1&L2 transactions

Add test-lang Fee & ForceExit option