core: review usages of (*intero.Context).BlockHeight method

This method returns persisted block height and doesn't take into account
persisting block height. Some of the callers of this method relay on
the wrong assumption that BlockHeight() returns persisting block index.

Fix improper usages of this method and adjust tests. Ref.
61a066583e/src/Neo/SmartContract/ApplicationEngine.cs (L634).

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>

pkg/core/interop/runtime/ext_test.go

@@ -691,11 +691,14 @@ func TestNotify(t *testing.T) {
 }
 
 func TestSystemRuntimeNotify_HFBasilisk(t *testing.T) {
-	const ntfName = "Hello, world!"
+	const (
+		ntfName       = "Hello, world!"
+		enabledHeight = 3
+	)
 
 	bc, acc := chain.NewSingleWithCustomConfig(t, func(c *config.Blockchain) {
 		c.Hardforks = map[string]uint32{
-			config.HFBasilisk.String(): 2,
+			config.HFBasilisk.String(): enabledHeight,
 		}
 	})
 	e := neotest.NewExecutor(t, bc, acc, acc)
@@ -738,6 +741,8 @@ func TestSystemRuntimeNotify_HFBasilisk(t *testing.T) {
 	}
 	ctrInv := e.NewInvoker(ctr.Hash, e.Validator)
 
+	// Block 0 is genesis.
+
 	// Block 1: deploy contract.
 	e.DeployContract(t, ctr, nil)
 
@@ -745,6 +750,7 @@ func TestSystemRuntimeNotify_HFBasilisk(t *testing.T) {
 	ctrInv.Invoke(t, nil, "main")
 
 	// Block 3: bad event should fault the execution.
+	require.Equal(t, uint32(enabledHeight-1), e.Chain.BlockHeight())
 	ctrInv.InvokeFail(t,
 		"System.Runtime.Notify failed: notification Hello, world! is invalid: parameter 0 type mismatch: Integer (manifest) vs Boolean (notification)",
 		"main")