Update Til with small fixes:
- L2Tx TxID & Type correctness done after Idxs setted
- Added PoolL2Tx signature for Exit type

Common:
- Add common.TxID Marshalers test

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 TxSel Nonce sort
- Fix surplus from refactors
- StateDB reuse computation of ToIdx across Synchronizer, TxSelector,
BatchBuilder

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.