fixed the bug with view triggers in object explorer (#639)

test/Microsoft.SqlTools.ServiceLayer.Test.Common/TestData/ObjectExplorer/TestScripts/AllSqlObjects.sql

@@ -241,6 +241,16 @@
 
 GO
 
+CREATE TRIGGER ViewTrigger on [HumanResources].[vEmployee] 
+INSTEAD OF INSERT
+AS
+BEGIN
+Update [HumanResources].[Employee] 
+   set JobTitle = 'Test1'
+   Where JobTitle = 'Test'
+END
+GO
+
 CREATE TABLE [dbo].[tableWithAllDataTypes](
 	[cDecimal] [decimal](18, 5) NULL,
 	[cNumeric] [numeric](18, 2) NULL,