- 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.