Extend ethclient test, implement new TxID spec

- Implement new TxID spec that distinguishes L1UserTx and L1CoordinatorTx
- Replace some type []*Foo by []Foo
- Fix HistoryDB & L2DB bug: in case of error, a rollback was applied and the returned error was nil
- Reorder inserts in historydb.NewHistoryDB() to follow foreign key dependencies
- Add initial synchronizer test with test.Client (for now, only tested l1UserTxs, blocks, addToken)
- Update L1UserTx event in test.Client

txselector/txselector_test.go

@@ -35,9 +35,9 @@ func initTest(t *testing.T, testSet string) *TxSelector {
 
 	return txsel
 }
-func addL2Txs(t *testing.T, txsel *TxSelector, poolL2Txs []*common.PoolL2Tx) {
+func addL2Txs(t *testing.T, txsel *TxSelector, poolL2Txs []common.PoolL2Tx) {
 	for i := 0; i < len(poolL2Txs); i++ {
-		err := txsel.l2db.AddTxTest(poolL2Txs[i])
+		err := txsel.l2db.AddTxTest(&poolL2Txs[i])
 		require.Nil(t, err)
 	}
 }