Update Infrastructure (#961)

* Update form .NET Core 2.2 to .NET Core 3.1

- Global variable for projects
- Change TFMs from netcoreapp2.2 to netcoreapp3.1
- Update global.json
- Update build.json
- Remove direct framework cake TestCore task
- Update travis dotnet version
- Update azure pipline file
- Update vscode launch.json

* Add Central Package Management

* Fix xUnit Breaking Change for MemberData type

* Fix xUnit breaking change for duplicate test method name

* Fix Rang/Index type conflict with System.Rang/Index

* Update vscode tasks.json

* Change serviceHostExecutable path in ServiceTestDriver.cs

* Downgrade SDK version (https://github.com/appveyor/ci/issues/3440)

- Appveyor hasn't installed latest SDK therefore I downgrade it until they install it.

* Dump Microsoft.SqlServer.DACFx

test/Microsoft.SqlTools.ServiceLayer.UnitTests/EditData/CellUpdateTests.cs

@@ -95,7 +95,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.EditData
             Assert.Equal(col, cu.Column);
         }
 
-        public static IEnumerable<object> ByteArrayTestParams
+        public static IEnumerable<object[]> ByteArrayTestParams
         {
             get
             {
@@ -158,7 +158,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.EditData
             Assert.Equal(col, cu.Column);
         }
 
-        public static IEnumerable<object> BoolTestParams
+        public static IEnumerable<object[]> BoolTestParams
         {
             get
             {
@@ -206,7 +206,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.EditData
             Assert.Equal(col, cu.Column);
         }
 
-        public static IEnumerable<object> RoundTripTestParams
+        public static IEnumerable<object[]> RoundTripTestParams
         {
             get
             {

test/Microsoft.SqlTools.ServiceLayer.UnitTests/EditData/RowEditBaseTests.cs

@@ -86,7 +86,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.EditData
             rt.ValidateWhereClauseSingleKey(nullClause);
         }
 
-        public static IEnumerable<object> GetWhereClauseIsNotNullData
+        public static IEnumerable<object[]> GetWhereClauseIsNotNullData
         {
             get
             {

test/Microsoft.SqlTools.ServiceLayer.UnitTests/EditData/SessionTests.cs

@@ -251,7 +251,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.EditData
             Assert.Throws<ArgumentOutOfRangeException>(() => testAction(s, rowId));
         }
 
-        public static IEnumerable<object> RowIdOutOfRangeData
+        public static IEnumerable<object[]> RowIdOutOfRangeData
         {
             get
             {
@@ -326,7 +326,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.EditData
             Assert.ThrowsAny<ArgumentException>(() => s.Initialize(initParams, c, qr, sh, fh));
         }
 
-        public static IEnumerable<object> InitializeNullParamsData
+        public static IEnumerable<object[]> InitializeNullParamsData
         {
             get
             {