Rename Transakcio to Til for a easier usage, also change til.TestContext
to til.Context, and til.NewTestContext to til.NewContext.

Transakcio:
- Transaction generation to fail when Transfer to an account that don't exist (not created yet)
- Add CreateAccountDepositCoordinator instruction feature
- Updated lang.go instruction type parser approach for more simplicity of code
- Remove `*testing.T` from transactions generation methods, use `log.Fatal` instead

Add transakcio set type definition, add set loading, move transakcio to
package, adapt branch to last master updates (fix compile due new common
types & git conflicts).
Update tests to pass the test, pending to adapt to new Transakcio
interface.

* 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